Pedestrian protection apparatus for vehicle

ABSTRACT

A pedestrian protection apparatus for a vehicle, including a plate member which is disposed at a front face of the vehicle, which includes front and rear portions, and which is fixed at the rear portion to the vehicle with at least a leading end part of the front portion protruded from the front face of the vehicle, the apparatus being arranged to sweep a leg portion of a pedestrian, thereby protecting the leg portion, wherein the leading end part includes at least one horizontally extending portion and a plurality of vertically extending portions each having an anterior surface substantially orthogonal to a horizontal plane, the horizontally extending portion and the vertically extending portions being formed integrally with the leading end part so as to be alternately disposed in the frontward and backward direction of the vehicle and extend in a staircase-like form.

The present application is based on Japanese Patent Application Nos.2005-368575 and 2005-377664 filed on Dec. 21, 2005 and Dec. 28, 2005,respectively, the contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a pedestrian protectionapparatus for a vehicle, and in particular to an improved structure ofthe pedestrian protection apparatus disposed at a lower part of a frontface of the vehicle and arranged to sweep a leg portion of a pedestrianby contact with the leg portion of the pedestrian that has collided withor contacted the front face of the vehicle, thereby protecting the legportion of the pedestrian.

2. Discussion of Related Art

In vehicles such as automotive vehicles, there are conventionallydisposed, at a front face, a rear face, or a side face, of the vehicles,various types of protection apparatus which absorb an impact energygenerated upon a collision for thereby protecting a vehicle body andpassengers of the vehicle. In recent years, there is disposed, at thefront face of the vehicle, an apparatus for protecting a pedestrian uponcollision or contact of the pedestrian with the front face of thevehicle.

As one type of the pedestrian protection apparatus, there is known aso-called leg-sweep apparatus which is disposed inside of a front bumperor disposed independently of the front bumper. The leg-sweep apparatusis arranged to apply, to a leg portion of the pedestrian, counterforcewith respect to an impact load that is inputted upon collision of thepedestrian with the front face of the vehicle and sweep (scoop up) theleg portion of the pedestrian, thereby causing the pedestrian to falldown or to be thrown over toward the vehicle. Thus, it is possible tominimize occurrence of injuries to the knee such as bone fractures,thereby assuring protection and safety of the pedestrian.

Examples of the leg-sweep apparatus as one type of the pedestrianprotection apparatus are disclosed in a patent publication document 1(JP-A-2001-277963) and a patent publication document 2(JP-A-2004-25976), for instance. The pedestrian protection apparatusdisclosed in the patent publication document 1 is arranged to bedisposed at the lower part of the front face of the vehicle and includesresin foam body which extends in a vehicle width direction with at leasta part of the resin foam body protruded from the front face of thevehicle and a beam member which extends in the vehicle width directionwhile being in contact with the back surface of the resin foam body. Thepedestrian protection apparatus disclosed in the patent publicationdocument 2 is arranged to be disposed at the lower part of the vehicleand includes a metal pipe or the like which is fixed to the lower partof the front face of the vehicle so as to extend in the vehicle widthdirection. However, the pedestrian protection apparatus disclosed inthose documents have drawbacks which should be rectified. In the formerpedestrian protection apparatus including the resin foam body and thebeam member, the number of the components is undesirably large, andtherefore the cost of the components is high. Further, it is troublesometo install or mount the apparatus on the vehicle. In the latterpedestrian protection apparatus including the metal pipe, the weight ofthe apparatus inevitably increases. In addition, it is difficult to forminto a configuration following that of the front face of the vehicle.

Under such situations, there has been proposed, in a patent publicationdocument 3 (JP-A-2004-203183), for instance, a pedestrian protectionapparatus arranged to be disposed to extend in a frontward and backwarddirection of a vehicle. The disclosed apparatus includes a plate memberwhich is formed of a synthetic resin, which includes a front portion anda rear portion, and which is fixed at the rear portion to the vehiclewith at least a leading end part of the front portion protruded from thefront face of the vehicle. The pedestrian protection apparatus disclosedin the patent publication document 3 is arranged to sweep a leg portionof a pedestrian that has collided with the front face of the vehicle bycontact of the leading end part of the front portion of the plate memberprotruding from the front face of the vehicle, with the leg portion ofthe pedestrian. In this conventional pedestrian protection apparatus,there are formed, on one surface of the front portion of the platemember, a plurality of first ribs having a planar shape and extending inthe frontward and backward direction of the vehicle and a plurality ofsecond ribs having a planar shape and extending in the width directionof the vehicle, which first and second ribs are assembled in a lattice.In this structure, the front portion of the plate member is reinforced,that is, the rigidity of the front portion of the plate member isincreased, owing to the ribs formed thereon.

In such a pedestrian protection apparatus, the number of the componentsis small. Further, the plate member whose leading end part is protrudedfrom the front face of the vehicle is made of the synthetic resin thatis excellent in formability. Accordingly, the disclosed apparatusassures protection of the pedestrian while eliminating the drawbacks ofthe above-indicated apparatus including the resin foam body and the beammember and the drawbacks of the above-indicated apparatus including themetal pipe. Further, the front portion of the plate member isreinforced, that is, the rigidity of the front portion is increased, bythe plurality of first and second ribs formed as described above,whereby, when the front portion of the plate member comes into contactwith the leg portion of the pedestrian, the front portion is preventedfrom being deformed due to impact upon the contact or the deformationamount of the front portion is made sufficiently small. Therefore, it ispossible to stably assure counterforce with respect to the impact loadinputted to the plate member.

However, the conventional pedestrian protection apparatus having theplate member formed of the synthetic resin experience the followingdrawbacks.

The above-described pedestrian protection apparatus is generallydisposed inside of the front bumper such that the planar second ribsprovided on the front portion of the plate member are opposed to theinner surface of the front bumper. The cross sectional shape of thefront bumper taken along a vertical plane which is parallel to thefrontward and backward direction of the vehicle is a convex curved shapeprotruding forward. Where the inner surface of the front bumper has aconvex curved surface configuration in correspondence with the shape ofthe front bumper, there is inevitably formed a comparatively largeclearance between the inner surface of the front bumper and the planarsecond ribs of the plate member.

Further, in the pedestrian protection apparatus described above, ingeneral, the leading end part of the front portion of the plate memberis positioned so as to protrude from the front face of the vehicle withthe rear portion of the plate member fixed to a radiator support, across member or the like. Accordingly, the dimension of the plate memberas measured in the frontward and backward direction of the vehicle isrelatively large. The increase in the dimension of the plate member asmeasured in the frontward and backward direction of the vehicle,however, leads to insufficient rigidity (insufficient strength withrespect to deformation) against the impact load inputted thereto uponcollision of the leg portion of the pedestrian with the front face ofthe vehicle. Where the flexural or bending rigidity of the plate memberis insufficient, the front portion of the plate member is initiallydeflected or bent with ease, so that the timing of initial rise of theimpact load in the load characteristics (abrupt rise of the load in theload-displacement curve) is delayed, thereby making it impossible toinstantaneously exhibit sufficient counterforce with respect to theimpact load. In this case, the pedestrian protection apparatus fails toinstantaneously or promptly sweep the leg portion of the pedestrian.

In the meantime, as the pedestrian protection apparatus which is to bedisposed inside of the front bumper with the leading end part of thefront portion of the plate member opposed to the inner surface of thefront bumper having the convex curved surface configuration, there isknown a structure that the surface of the leading end part of the platemember that confronts the inner surface of the front bumper is made as aconvex curved surface corresponding to the inner surface of the frontbumper, as disclosed in a patent publication document 4(JP-A-2002-274298), for instance. The disclosed structure preventsformation of a large clearance between the leading end part of the platemember and the inner surface of the front bumper.

In the pedestrian protection apparatus having such a structure, however,the impact load that acts in a backward direction of the vehicle whenthe leg portion of the pedestrian collides with the front bumper isinputted to the convex curved surface of the leading end part of theplate member. Accordingly, upon inputting of the impact load, there isgenerated force that lifts up the leading end part of the plate portion.In this instance, the leading end part of the plate member is deformedso as to be rolled up, resulting in a delay in the rise of the impactload in the load characteristics. Accordingly, the pedestrian protectionapparatus in which the leading end part of the plate member has a shapethat corresponds to the shape of the inner surface of the front bumperalso suffers from the problem that the leg portion of the pedestriancannot be promptly swept.

SUMMARY OF THE INVENTION

The present invention has been developed in the light of theaforementioned situations. It is therefore an object of the invention toprovide a pedestrian protection apparatus for a vehicle capable ofsufficiently protecting a leg portion of a pedestrian that has collidedwith a front face of the vehicle by promptly and reliably sweeping theleg portion of the pedestrian.

The above-indicated object of the invention may be attained according toa first aspect of the invention, which provides a pedestrian protectionapparatus for a vehicle, comprising a plate member which is disposed ata lower part of a front face of the vehicle so as to extend in afrontward and backward direction of the vehicle, which is made of asynthetic resin, which includes a front portion and a rear portion, andwhich is fixed at the rear portion to the vehicle with at least aleading end part of the front portion protruded from the front face ofthe vehicle, the apparatus being arranged to sweep a leg portion of apedestrian that has collided with the front face of the vehicle bycontact of the leading end part of the front portion of the plate memberwith the leg portion of the pedestrian, thereby protecting the legportion of the pedestrian, wherein the leading end part of the frontportion of the plate member includes at least one horizontally extendingportion each of which extends horizontally in the frontward and backwarddirection of the vehicle and a plurality of vertically extendingportions each of which has an anterior surface substantially orthogonalto a horizontal plane and each of which extends in a vertical direction,the at least one horizontally extending portion and the plurality ofvertically extending portions being formed integrally with the leadingend part such that each of the at least one horizontally extendingportion and each of the plurality of vertically extending portions arealternately disposed in the frontward and backward direction of thevehicle so as to extend in a staircase-like form, whereby the leadingend part has a staircase-like portion constituted by the at least onehorizontally extending portion and the plurality of vertically extendingportions.

The “horizontally extending” state mentioned in the presentspecification is not strictly limited to a state of extending straightlyin a horizontal direction, but includes a state of extending whileinclining with respect to the horizontal direction by a slight angle.Similarly, the “vertically extending” state is not strictly limited to astate of extending straightly in a vertical direction, but includes astate of extending while inclining with respect to the verticaldirection by a slight angle. Further, “an anterior surface substantiallyorthogonal to a horizontal plane” includes both of a flat surface or acurved surface formed by a moving path of a vertical line and a flatsurface or a curved surface formed by a moving path of a straight linethat is inclined with respect to the vertical direction by a slightangle. Hereinafter, these terms are used in the respective meaningsdescribed above.

In the pedestrian protection apparatus constructed according to theabove-indicated first aspect of the invention, the impact load generatedaccompanied by the collision of the leg portion of the pedestrian isinputted, at the leading end part of the plate member, substantiallyperpendicularly to the anterior surface of each of the plurality ofvertically extending portions in the staircase-like portion.Accordingly, unlike the conventional apparatus in which the front faceof the leading end part of the plate member is made as a convex curvedsurface corresponding to the inner surface of the front bumper whosevertical cross sectional shape is the above-described convex curvedshape, the present apparatus does not suffer from force that lifts upthe leading end part of the plate member upon inputting of the impactload thereto, so that it is possible to advantageously eliminate orrestrain the delay of the rise of the impact load in the loadcharacteristics due to occurrence of deformation of the leading end partof the plate member so as to be rolled up. In addition, upon thecollision with the leg portion of the pedestrian, the area of theleading end part of the plate member which comes into contact with theleg portion of the pedestrian can be made large. Consequently, theimpact load can be reliably and sufficiently inputted to the leading endpart of the plate member, allowing larger counterforce to be exhibited.

In the present apparatus, a part of or an entirety of the leading endpart of the plate member is formed by the staircase-like portionconstituted by the plurality of vertically extending portions and the atleast one horizontally extending portion. According to the arrangement,at the leading end part of the plate member, the plurality of verticallyextending portions are located at mutually different height levels inthe forward and backward direction with each of the at least onehorizontally extending portion being interposed between adjacent two ofthe plurality of vertically extending portions. Therefore, even wherethe leading end part of the plate member is deposed inside of the frontbumper whose vertical cross sectional shape is the curved convex shape,such that the leading end part of the plate member is opposed to theinner surface of the front bumper having the curved convex shape, theclearance formed between the inner surface of the front bumper and theanterior surface of each vertically extending portion can be minimized.

Because the staircase-like portion includes the at least onehorizontally extending portion, there are formed portions extending in adirection in which the impact load is inputted (i.e., horizontalportions extending in the horizontal direction that is the frontward andbackward direction of the vehicle) at a plural locations of the platemember such that those portions have mutually different height levels.Accordingly, the counterforce with respect to the impact load can besufficiently exhibited at the plurality of locations. Moreover, theportions of the plate portion that extend in the input direction of theimpact load are in a divided state, so that moment arm in the platemember can be advantageously shortened, thereby reducing rotation forcegenerated in the plate member upon inputting of the impact thereto.Therefore, it is possible to prevent, with high reliability, the leadingend part of the plate member from being deformed to be rolled up,resulting in a prompt rise of the impact load in the loadcharacteristics.

In the pedestrian protection apparatus constructed as described above,it is possible to promptly and reliably sweep, with sufficientcounterforce, the leg portion of the pedestrian that has collided withthe front face of the vehicle even when the apparatus is disposedindependently of the front bumper and even when the apparatus isdisposed inside of the front bumper whose vertical cross sectional shapeis the convex curved shape. As a result, the present apparatus iscapable of sufficiently protecting the leg portion of the pedestrian ata higher level.

Because the present pedestrian protection apparatus permits a promptrise of the impact load in the load characteristics, the impact loadreaches a target value quickly. Accordingly, the present pedestrianprotection apparatus effectively assures a sufficient amount of theimpact-absorbing stroke accompanied by buckling deformation of thehorizontally extending portion after the impact load in the loadcharacteristics has reached the target value.

The above-indicated object of the present invention may also be attainedaccording to a second aspect of the invention, which provides apedestrian protection apparatus for a vehicle, comprising a plate memberwhich is disposed at a lower part of a front face of the vehicle so asto extend in a frontward and backward direction of the vehicle with asuitable width, which is made of a synthetic resin, which includes afront portion and a rear portion, and which is fixed at the rear portionto the vehicle with at least a leading end part of the front portionprotruded from the front face of the vehicle, the apparatus beingarranged to sweep a leg portion of a pedestrian that has collided withthe front face of the vehicle by contact of the leading end part of thefront portion of the plate member with the leg portion of thepedestrian, thereby protecting the leg portion of the pedestrian,wherein the plate member includes: a horizontally extending portionwhich is located at the leading end part of the front portion of theplate member so as to horizontally extend over an entire width of theplate member; a front-side vertically extending portion which is formedintegrally with a front end of the horizontally extending portion so asto extend in a vertical direction; a rear-side vertically extendingportion which is formed integrally with a rear end of the horizontallyextending portion so as to extend in the vertical direction such thatthe rear-side vertically extending portion is opposed to the front-sidevertically extending portion with a suitable distance interposedtherebetween; and a connecting portion which is constituted by aproximal end part of the front portion of the plate member that extendsin the frontward and backward direction on the back side of therear-side vertically extending portion and which connects, integrally tothe rear portion of the plate member, a posterior surface of therear-side vertically extending portion at a point thereof having aheight position different from a height position of a connecting pointof an anterior surface of the rear-side vertically extending portion atwhich the rear-side vertically extending portion is connected to thehorizontally extending portion, and wherein the front portion of theplate member is constituted by including, at the leading end partthereof, a U-shaped portion having a U-shaped configuration in verticalcross section.

Concerning the “horizontally extending” state and the “verticallyextending” state, the explanation made above with respect to the firstaspect is applicable.

In the pedestrian protection apparatus constructed according to theabove-indicated second aspect of the invention, the U-shaped portionprovided at the leading end part of the front portion of the platemember functions as a bead that reinforces the front portion of theplate member. Accordingly, even when the entire length of the platemember (i.e., the dimension of the plate member as measured in thefrontward and backward direction of the vehicle) is relatively large, itis possible to sufficiently assure bending or flexural strength of thefront portion, in particular, the rigidity (the strength with respect todeformation) against the impact load inputted thereto upon the collisionof the leg portion of the pedestrian with the front face of the vehicle.Therefore, the front portion of the plate member is advantageouslyprevented from easily deflected upon inputting of the impact load.

In the pedestrian protection apparatus constructed according to theabove-indicated second aspect of the invention, when the leg portion ofthe pedestrian comes into contact with the leading end part of the frontportion of the plate member as a result of collision of the leg portionagainst the front face of the vehicle, the front-side verticallyextending portion is deformed so as to be inclined with respect to thevertical direction by a suitable angle while the horizontally extendingportion is displaced backward. Further, the rear-side verticallyextending portion is deformed so as to be inclined with respect to thevertical direction by a suitable angle. Accordingly, the impact load isdesigned to be gradually transmitted from the front portion to the rearportion of the plate member. In this instance, since the front-side andthe rear-side vertically extending portions are formed to extend in thevertical direction over the entire width of the plate member, thosefront-side and rear-side vertically extending portions are deformed overa wide range in the width direction of the plate ember (i.e., in thevehicle width direction), whereby the impact load can be effectivelytransmitted also in the width direction of the plate member. As aresult, the impact load is advantageously distributed in the frontportion of the plate member, so that the leading end part of the platemember is effectively prevented from being easily deflected.

Moreover, in the present apparatus, the impact load generated by thecollision of the leg portion of the pedestrian is inputted substantiallyperpendicularly with respect to the front-side vertically extendingportion located at the leading end part of the plate member. Accordingto the arrangement, there is generated no force that lifts up theleading end part of the plate member upon inputting of the impact loadthereto, thereby effectively preventing the leading end part of theplate member from being deformed, i.e., rolled up.

Thus, in the pedestrian protection apparatus constructed according tothe second aspect of the invention, the front portion of the platemember is effectively prevented from being easily deformed or deflectedby the impact load, arising from insufficient rigidity with respect tothe impact load, concentration of stress of the impact load, theconfiguration of the leading end part of the plate portion, and thelike. As a result, the delay of the rise of the impact load in the loadcharacteristics can be obviated.

The pedestrian protection apparatus constructed as described abovepermits a prompt rise of the impact load in the load characteristics andthereby instantaneously exhibits a sufficient degree of counterforcewith respect to the impact load. Consequently, the present pedestrianprotection apparatus is capable of promptly and reliably sweep the legportion of the pedestrian collided with the front face of the vehicle,thereby protecting the leg portion with higher reliability.

Because the present pedestrian protection apparatus permits a promptrise of the impact load in the load characteristics as described above,the impact load reaches a target value more quickly. Accordingly, thepresent pedestrian protection apparatus effectively assures a sufficientamount of the impact-absorbing stroke accompanied by bucklingdeformation of the horizontally extending portion after the impact loadin the load characteristics has reached the target value.

FORMS OF THE INVENTION

The present invention is preferably practiced in at least the followingforms.

(1) A pedestrian protection apparatus for a vehicle, comprising a platemember which is disposed at a lower part of a front face of the vehicleso as to extend in a frontward and backward direction of the vehicle,which is made of a synthetic resin, which includes a front portion and arear portion, and which is fixed at the rear portion to the vehicle withat least a leading end part of the front portion protruded from thefront face of the vehicle, the apparatus being arranged to sweep a legportion of a pedestrian that has collided with the front face of thevehicle by contact of the leading end part of the front portion of theplate member with the leg portion of the pedestrian, thereby protectingthe leg portion of the pedestrian,

wherein the leading end part of the front portion of the plate memberincludes at least one horizontally extending portion each of whichextends horizontally in the frontward and backward direction of thevehicle and a plurality of vertically extending portions each of whichhas an anterior surface substantially orthogonal to a horizontal planeand each of which extends in a vertical direction, the at least onehorizontally extending portion and the plurality of vertically extendingportions being formed integrally with the leading end part such thateach of the at least one horizontally extending portion and each of theplurality of vertically extending portions are alternately disposed inthe frontward and backward direction of the vehicle so as to extend in astaircase-like form, whereby the leading end part has a staircase-likeportion constituted by the at least one horizontally extending portionand the plurality of vertically extending portions.

(2) The apparatus according to the above form (1),

wherein a forward end of the staircase-like portion is constituted byone of the plurality of vertically extending portions, and

wherein one of vertically opposite ends of the one of the plurality ofvertically extending portions that is nearer to one of the at least onehorizontally extending portion which is adjacent to the one of theplurality of vertically extending portions is located at a middleportion of the staircase-like portion (including the vicinity of themiddle portion) in a height direction thereof.

According to the above-indicated form (2), upon collision of the legportion of the pedestrian against the front face of the vehicle, the legportion is initially brought into contact with the front end of thehorizontally extending portion located at the middle portion of thestaircase-like portion in its height direction. Accordingly, the impactload acts, with high reliability, on the leading end part of the platemember in the horizontal direction, whereby the leading end part of theplate member is more effectively prevented from being deformed or rolledup. As a result, the leg portion of the pedestrian can be moreefficiently and reliably protected.

(3) The apparatus according to the above form (1), wherein a forward endof the staircase-like portion is constituted by one of the at least onehorizontally extending portion.

According to the above-indicated form (3), when the present pedestrianprotection apparatus is disposed inside of the front bumper having theconvex curved configuration in the vertical cross section, a clearancebetween the inner surface of the front bumper and the leading end partof the plate member can be made small, thereby effectively assuring aprompt rise of the impact load in the load characteristics. Hence, theprotection of the leg portion of the pedestrian can be realized at ahigher level.

(4) The apparatus according to any one of the above forms (1)-(3),wherein reinforcing ribs for reinforcing the front portion of the platemember are formed on a part of the front portion that at least includesthe staircase-like portion, such that the reinforcing ribs are integralwith posterior surfaces of the plurality of vertically extendingportions in the staircase-like portion, so as to extend in the frontwardand backward direction of the vehicle.

According to the above-indicated from (4), the rigidity of the frontportion of the plate member can be advantageously increased, therebypermitting the counterforce with respect to the impact load to besufficiently exhibited. In consequence, the function of protecting theleg portion of the pedestrian can be effectively enhanced. Further, byadjusting the number, the location, etc., of the reinforcing ribs whichare provided on the part of the front portion of the plate member thatat least includes the staircase-like portion, the rigidity of the frontportion of the plate member can be suitably changed, whereby the amountof buckling deformation of the front portion of the plate memberaccompanied by the input of the impact load can be easily tuneddepending upon the magnitude of the impact load to be inputted.

(5) A pedestrian protection apparatus for a vehicle, comprising a platemember which is disposed at a lower part of a front face of the vehicleso as to extend in a frontward and backward direction of the vehiclewith a suitable width, which is made of a synthetic resin, whichincludes a front portion and a rear portion, and which is fixed at therear portion to the vehicle with at least a leading end part of thefront portion protruded from the front face of the vehicle, theapparatus being arranged to sweep a leg portion of a pedestrian that hascollided with the front face of the vehicle by contact of the leadingend part of the front portion of the plate member with the leg portionof the pedestrian, thereby protecting the leg portion of the pedestrian,

wherein the plate member includes: a horizontally extending portionwhich is located at the leading end part of the front portion of theplate member so as to horizontally extend over an entire width of theplate member; a front-side vertically extending portion which is formedintegrally with a front end of the horizontally extending portion so asto extend in a vertical direction; a rear-side vertically extendingportion which is formed integrally with a rear end of the horizontallyextending portion so as to extend in the vertical direction such thatthe rear-side vertically extending portion is opposed to the front-sidevertically extending portion with a suitable distance interposedtherebetween; and a connecting portion which is constituted by aproximal end part of the front portion of the plate member that extendsin the frontward and backward direction on the back side of therear-side vertically extending portion and which connects, integrally tothe rear portion of the plate member, a posterior surface of therear-side vertically extending portion at a point thereof having aheight position different from a height position of a connecting pointof an anterior surface of the rear-side vertically extending portion atwhich the rear-side vertically extending portion is connected to thehorizontally extending portion, and

wherein the front portion of the plate member is constituted byincluding, at the leading end part thereof, a U-shaped portion having aU-shaped configuration in vertical cross section.

(6) A pedestrian protection apparatus for a vehicle, comprising a platemember which is disposed at a lower part of a front face of the vehicleso as to extend in a frontward and backward direction of the vehiclewith a suitable width, which is made of a synthetic resin, whichincludes a front portion and a rear portion, and which is fixed at therear portion to the vehicle with at least a leading end part of thefront portion protruded from the front face of the vehicle, theapparatus being arranged to sweep a leg portion of a pedestrian that hascollided with the front face of the vehicle by contact of the leadingend part of the front portion of the plate member with the leg portionof the pedestrian, thereby protecting the leg portion of the pedestrian,

wherein the plate member includes: a front-side vertically extendingportion which is located at the leading end part of the front portion ofthe plate member so as to vertically extend over an entire width of theplate member; a plurality of rear-side vertically extending portionswhich are located at the back of the front-side vertically extendingportion with a suitable distance interposed therebetween so as to extendin the vertical direction over the entire width of the plate member suchthat the plurality of rear-side vertically extending portions areopposed to the front-side vertically extending portion and spaced apartfrom each other by a suitable distance in the frontward and backwarddirection; a plurality of horizontally extending portions which arelocated between mutually corresponding vertical ends of a forwardmostone of the plurality of rear-side vertically extending portions and thefront-side vertically extending portion and between mutuallycorresponding vertical ends of the plurality of rear-side verticallyextending portions, such that the plurality of horizontally extendingportions horizontally extend over the entire width of the plate memberand such that adjacent two of the plurality of horizontally extendingportions in the frontward and backward direction are located at mutuallydifferent height levels, thereby connecting the front-side verticallyextending portion and the forwardmost one of the plurality of rear-sidevertically extending portions integrally to each other and connectingthe plurality of rear-side vertically extending portions to each other;and a connecting portion which is constituted by a proximal end part ofthe front portion of the plate member that is located on the back sideof a rearmost one of the plurality of rear-side vertically extendingportions so as to extend in the frontward and backward direction andwhich connects, integrally to the rear portion of the plate member, aposterior surface of the rearmost one of the plurality of rear-sidevertically extending portions at a point thereof having a differentheight position from that of a connecting point of an anterior surfaceof the rearmost one of the plurality of vertically extending portions atwhich the rearmost one of the plurality of vertically extending portionsis connected to a corresponding one of the plurality of horizontallyextending portions, and

wherein the leading end part of the front portion of the plate memberextends in a zigzag form in a height direction with a U-shapedconfiguration in vertical cross section.

According to the above-indicated form (6), the leading end part of thefront portion of the plate member has a U-shaped configuration invertical cross section and is made as a zigzag portion in which theU-shaped portion functioning as a bead is continuously formed in thefrontward and backward direction. Accordingly, the rigidity with respectto the impact load can be advantageously increased at the front portionof the plate member. Further, the present apparatus includes, inaddition to the front-side vertically extending portion to which theimpact load is inputted substantially perpendicularly, the plurality ofhorizontally extending portions which are displaced backward uponinputting of the impact load and the plurality of rear-side verticallyextending portions which are deformed so as to be inclined with respectto the vertical direction by a prescribed angle. Accordingly, the impactload can be more sufficiently transmitted toward the width direction ofthe plate member and effectively distributed.

The above-indicated form (6), therefore, permits a prompt rise of theimpact load in the load characteristics, so that sufficient counterforcewith respect to the impact load can be exhibited at earlier timing. As aresult, the leg portion of the pedestrian collided with the front faceof the vehicle can be instantaneously and reliably swept, assuringfurther enhanced performance of protecting the leg portion of thepedestrian.

Because the above-indicated form (6) permits a prompt rise of the impactload in the load characteristics, the impact load can reach a targetvalue quickly, thereby effectively assuring a sufficient amount of theimpact-absorbing stroke accompanied by buckling deformation of thehorizontally extending portion after the impact load in the loadcharacteristics has reached the target value.

(7) The apparatus according to the above form (5) or (6), wherein thefront-side vertically extending portion is bent at substantially rightangles at a plurality of locations of a middle portion thereof as seenin a height direction thereof, so as to extend in the vertical directionin a staircase-like form.

According to the above-indicated form (7), there are formed portionsthat extend horizontally, at a plural locations of the staircase-likeportion located at the leading end part of the front portion of theplate member, such that those portions are in a divided state.Accordingly, moment arm in front portion of the plate member can beadvantageously shortened, thereby reducing rotation force generated inthe front portion of the plate member upon inputting of the impactthereto. Therefore, it is possible to prevent, with high reliability,the front portion of the plate member from being easily deflected,resulting in a prompt rise of the impact load in the loadcharacteristics.

Further, according to the above-indicated form (7), the plurality ofportions which extend horizontally and which are provided at the leadingend part of the plate member are located at mutually different heightlevels in the frontward and backward direction. Therefore, where thepresent pedestrian protection apparatus is disposed inside of the frontbumper having the convex curved configuration in vertical cross sectionsuch that the leading end part of the front portion of the plate memberis opposed to the inner surface of the front bumper constituted by theconvex curved surface, it is possible to minimize a clearance formedbetween the inner surface of the front bumper and the front face of theleading end part of the plate member. Therefore, it is possible toeffectively eliminate or restrain the delay of the rise of the impactload in the load characteristics arising from the presence of theclearance between the inner surface of the front bumper and the leadingend part of the plate member.

Accordingly, the above-indicated form (7) permits sufficientcounterforce with respect to the impact load to be exhibitedinstantaneously, so that the leg portion of the pedestrian collided withthe front face of the vehicle can be promptly and reliably swept,assuring advantageously enhanced performance of protection of the legportion of the pedestrian.

(8) The apparatus according to any one of the above forms (5)-(7),wherein reinforcing portions for increasing strength of the frontportion of the plate member is provided on the front portion, so as toprevent easy deformation of the front portion due to an impact loadapplied thereto resulting from collision of the leg portion of thepedestrian with the front face of the vehicle.

According to the above-indicated form (8), it is possible to effectivelyeliminate or restrain easy deflection of the front portion of the platemember by the impact load arising from insufficient rigidity withrespect to the impact load. As a result, the above-indicated form (8)effectively realizes a prompt rise of the impact load in the loadcharacteristics and improvement of the function of protecting the legportion of the pedestrian.

(9) The apparatus according to the above form (8), wherein thereinforcing portions are constituted by reinforcing ribs formedintegrally on the front portion of the plate member such that thereinforcing ribs are integral with a posterior surface of the front-sidevertically extending portion and posterior surfaces of the plurality ofrear-side vertically extending portions, so as to extend in thefrontward and backward direction.

According to the above-indicated form (9), the reinforcing portionsexhibiting excellent characteristics indicated above are easily formedby molding using metallic dies, Accordingly, the reinforcing portionsare advantageously realized in a comparatively simple and moderatestructure without increasing the number of the components. Further, byadjusting the installation structure (i.e., the number and the location)of the reinforcing ribs provided on the front portion of the platemember, the rigidity of the front portion of the plate member can besuitably changed, thereby making it possible to easily tune the amountof the buckling deformation of the front portion of the plate memberaccompanied by the input of the impact load and the amount of absorptionof the impact energy based on the buckling deformation of the frontportion, depending upon the magnitude of the impact load to be inputted.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, advantages and technical andindustrial significance of the present invention will be betterunderstood by reading the following detailed description of presentlypreferred embodiments of the invention, when considered in connectionwith the accompanying drawings, in which:

FIG. 1 is a top plan view showing a pedestrian protection apparatusconstructed according to a first embodiment of the invention;

FIG. 2 is a cross sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is an explanatory view showing a state in which the pedestrianprotection apparatus of FIG. 1 is installed on a vehicle;

FIG. 4 is an explanatory view showing a state in which a pedestrianprotection apparatus constructed according to a second embodiment of theinvention is installed on a vehicle;

FIG. 5 is a top plan view showing a pedestrian protection apparatusconstructed according to a third embodiment of the invention:

FIG. 6 is a cross sectional view taken along line 6-6 of FIG. 5;

FIG. 7 is an explanatory view showing a state in which the pedestrianprotection apparatus of FIG. 5 is installed on a vehicle;

FIG. 8 is an explanatory view showing a deformation state of thepedestrian protection apparatus of FIG. 5 upon collision of a pedestrianwith a front face of the vehicle;

FIG. 9 is an explanatory view showing a state in which a pedestrianprotection apparatus constructed according to a fourth embodiment of theinvention is installed on a vehicle;

FIG. 10 is an explanatory view showing a state in which a pedestrianprotection apparatus constructed according to a fifth embodiment of theinvention is installed on a vehicle;

FIG. 11 is an explanatory view showing simulation results of the amountof partial deformation of the present pedestrian protection apparatusdue to the impact load obtained by conducting a pedestrian collisiontest on the present pedestrian protection apparatus; and

FIG. 12 is an explanatory view showing simulation results of the amountof partial deformation of a conventional pedestrian protection apparatusdue to the impact load obtained by conducting a pedestrian collisiontest on the conventional pedestrian protection apparatus.

DETAILED DESCRIPTION OF THE INVENTION

To further clarify the present invention, there will be described indetail embodiments of the invention with reference to the accompanyingdrawings.

Referring first to the plan view of FIG. 1 and the vertical crosssectional view of FIG. 2, there is schematically shown a leg-sweepapparatus as a pedestrian protection apparatus constructed according toa first embodiment of the present invention. The leg-sweep apparatusgenerally indicated at 10 in FIGS. 1 and 2 is arranged to be installedinside of a front bumper which is disposed at a front face of anautomotive vehicle. As apparent from FIGS. 1 and 2, the presentleg-sweep apparatus 10 includes a base plate 12 as a plate member.

The base plate 12 is formed of a synthetic resin material such aspolypropylene or ABS resin and is constituted by a thin planar platehaving a generally rectangular shape. In the base plate 12, thedimension as measured in a vertical direction of FIG. 1, i.e., thedimension as measured in a vehicle width direction or a leftward andrightward (lateral) direction of the vehicle under installation of theleg-sweep apparatus 10 on the vehicle, is made smaller than the vehiclewidth by a suitable amount, and the dimension as measured in atransverse direction of FIG. 1, i.e., the dimension as measured in afrontward and backward direction of the vehicle (a vehicle length orrunning direction), is made sufficiently smaller than theabove-indicated dimension as measured in the leftward and rightwarddirection.

The base plate 12 includes a front portion 14 which occupies asubstantially front half region thereof and a rear portion 16 whichoccupies a substantially rear half region thereof. The front portion 14of the base plate 12 has, on its upper surface, a plurality of firstreinforcing rigs 18 (here, fourteen ribs 18) each of which is a thinplanar plate and which are formed integrally with the front portion 14such that each first reinforcing rib 18 continuously and straightlyextends with a constant height from a forward end of the front portion14 toward a backward end thereof over the entire length of the frontportion 14 as measured in the frontward and backward direction. Thefirst reinforcing ribs 18 are opposed to and spaced apart from eachother by a suitable constant distance and located parallel to eachother, in the leftward and rightward direction.

At a leading end (front end) part 22 of the upper surface of the frontportion, 14, there are provided, in addition to front-side parts of therespective first reinforcing ribs 18, a plurality of second reinforcingribs 20 (here, fifteen ribs 20) each having the same thickness andheight as those of the first reinforcing ribs 18 and having a lengthshorter than that of the first reinforcing ribs 18. The secondreinforcing ribs 20 each of which is a thin planar plate are formedintegrally with the leading end part 22 so as to continuously andstraightly extend in the frontward and backward direction such that eachsecond reinforcing rib 20 is interposed between adjacent two of thefirst reinforcing ribs 18 that are opposed to each other. The secondreinforcing ribs 20 are located parallel to the first reinforcing ribs18 adjacent thereto. Further, any adjacent two of the second reinforcingribs 20 which sandwich a corresponding one of the first reinforcing ribs18 therebetween are located parallel to each other.

The rear portion 16 of the plate base plate 12 has flat upper and lowersurfaces on which no reinforcing ribs 18, 20 are formed. At one end ofthe rear portion 16 remote from the front portion 14, a plurality ofinsertion holes 23 (here, five insertion holes 23) into each of which asuitable fixing bolt is insertable are formed through the thickness ofthe rear portion 16 such that the insertion holes 23 are spaced apartfrom each other by a suitable distance in the leftward and rightwarddirection.

In the exemplary first embodiment, the leg-sweep apparatus 10 isattached, at its rear portion 16, to a prescribed portion of the vehicleso as to be positioned horizontally, as shown in FIG. 3. The frontportion 14 of the base plate 12 on which the reinforcing ribs 18, 20 areformed has a higher degree of rigidity with respect to bending orflexural load, i.e., a higher degree of deformation strength withrespect to the impact load inputted thereto in the frontward andbackward direction in a state in which the leg-sweep apparatus 10 isinstalled on the vehicle, than that of the rear portion 16 on which noreinforcing ribs 18, 20 are formed. In such a front portion 14, theleading end part 22 on which are formed both of the front-side parts ofthe respective first reinforcing ribs 18 and the second reinforcing ribs20 is constructed to have a higher degree of rigidity than the rest ofthe front portion 14 other than the leading end part 22.

In the present leg-sweep apparatus 10, in particular, the leading endpart 22 of the front portion 14 of the base plate 12 on which are formedthe second reinforcing ribs 20 has a special structure not found inconventional apparatus.

Namely, the leading end part 22 of the front portion 14 of the baseplate 12 is in a bent form obtained by bending a flat plate extendingstraightly in the frontward and backward direction, at right angles inthe frontward and backward direction at three locations that are spacedapart from each other by a prescribed distance in the frontward andbackward direction over the entire width thereof. In such a bent form,the leading end part 22 is formed with first, second and third bends 26,28, 30 in order as seen from the front side, as shown in FIG. 2.

In the thus configured leading end part 22 of the base plate 12, aportion thereof located behind the first bend 26 is made as a firsthorizontally extending portion 32 that extends horizontally andstraightly in the frontward and backward direction under installation ofthe leg-sweep apparatus 10 on the vehicle. A portion of the leading endpart 22 between the first bend 26 and the second bend 28 extends uprightat right angles from the front end of the first horizontally extendingportion 32 and is made as a first vertically extending portion 34 thatextends straightly in the vertical direction under installation of theleg-sweep apparatus 10 on the vehicle. A portion of the leading end part22 between the second bend 28 and the third bend 30 is bent at rightangles from the upper end of the first vertically extending portion 34and is made as a second horizontally extending portion 36 thathorizontally and straightly extend in the frontward and backwarddirection under installation of the leg-sweep apparatus 10 on thevehicle. A portion of the leading end part 22 located forward of thethird bend 30 (i.e., the forward end of the leading end part 22) extendsupright at right angles from the front end of the second horizontallyextending portion 36 and is made as a second vertically extendingportion 38 that extends straightly in the vertical direction underinstallation of the leg-sweep apparatus 10 on the vehicle.

In other words, in the leading end part 22 of the front portion 14 ofthe base plate 12, the second vertically extending portion 38 and thefirst vertically extending portion 34 are respectively located on thefront side and the back side of the second horizontally extendingportion 36 with the same 36 interposed therebetween, such that theformer 38 is located at a height position higher than that of the latter34. The second horizontally extending portion 36 and the firsthorizontally extending portion 32 are respectively located on the frontside and the back side of the first vertically extending portion 34 withthe same 34 interposed therebetween, such that the former 36 is locatedat a height position higher than that of the latter 32. These extendingportions 32-38 are connected integrally to each other at the three bends26-30.

Thus, in the leading end part 22 of the front portion 14 of the baseplate 12, each of the first and second horizontally extending portions32, 36 and each of the first and second vertically extending portions34, 38 are alternately disposed in the frontward and backward directionso as to extend in a staircase-like form, whereby the entirety of theleading end part 22 is made as a staircase-like portion 40 constitutedby the first and second horizontally extending portions 32, 36 and thefirst and second vertically extending portions 34, 38.

In the thus formed staircase-like portion 40, the anterior surface ofthe first vertically extending portion 34 and the anterior surface ofthe second vertically extending portion 38 are respectively made asload-input surfaces 42, 43 to which the impact load generated by thecollision of the leg portion of the pedestrian is to be inputted. Eachof the load-input surfaces 42, 43 extends straightly in the verticaldirection and has a curved surface configuration obtained by deflectingor warping a vertical plane which is right-angled with respect to ahorizontal plane that includes the direction of input of the impact loadgenerated by the collision of the leg portion of the pedestrian, suchthat the vertical plane is gradually curved backward from the middleportion thereof as seen in the leftward and rightward direction towardthe opposite end portions thereof as seen in the same direction. Namely,each of the load-input surfaces 42, 43 is constituted as a convex curvedsurface which protrudes forward and which is formed by a path that isobtained by moving a vertical line so as to draw an arc.

Because the first and second vertically extending portions 34, 38 aredisposed as mentioned above, the load-input surface 43 of the secondvertically extending portion 38 is located above the load-input surface42 of the first vertically extending portion 34 at a location away fromthe load-input surface 42 in the forward direction by a distancecorresponding to the length of the second horizontally extending portion36 as measured in the frontward and backward direction of the vehicle.

Here, the first and second vertically extending portions 34, 38 have thesame height (i.e., the same dimension as measured in the direction ofextension thereof), whereby the first and second vertically extendingportions 34, 38 have substantially the same area. Further, the lower endof the second vertically extending portion 38, i.e., the third bend 30as the front end of the second horizontally extending portion 36interposed between those two vertically extending portions 34, 38 islocated at the substantially middle of the staircase-like portion 40 inthe height direction thereof.

The first reinforcing ribs 18 and the second reinforcing ribs 20provided on the front portion 14 of the base plate 12 are formedintegrally with the back surfaces of the load-input surfaces 42, 43 ofthe respective first and second vertically extending portions 34, 38 andthe upper surfaces of the respective first and second horizontallyextending portions 32, 36.

The thus constructed leg-sweep apparatus 10 is disposed inside of afront bumper 44 installed on the front face of the vehicle, as shown inFIG. 3, for example.

The front bumper 44 inside of which is disposed the leg-sweep apparatus10 has a bumper cover 50 including an upper protruding portion 46 and alower protruding portion 48 which protrude from the front face of thevehicle in a state in which the front bumper 44 is installed on thefront face of the vehicle. Each of the upper and lower protrudingportions 46, 48 has, in vertical cross section, a convex curved surfaceconfiguration protruding forward. The bumper cover 50 of the frontbumper 44 is fixed by bolts or the like to a front grille 51, forinstance, that constitutes the front face portion of the vehicle. InFIG. 3, the reference numerals 52, 54 denote a bonnet and a radiator,respectively.

A known impact or shock-absorbing member 56 whose rigidity is smallerthan that of the leg-sweep apparatus 10 is disposed inside of the upperprotruding portion 46 of the bumper cover 50 installed on the front faceof the vehicle such that the impact-absorbing member 56 is fixedlyinterposed between the upper protruding portion 46 and a bumperreinforcement 58 as a rigid member while the leg-sweep apparatus 10 isdisposed inside of the lower protruding portion 48 of the bumper cover50.

More specifically described, the leg-sweep apparatus 10 is disposedinside of the lower protruding portion 48 of the bumper cover 50 suchthat the staircase-like portion 40 (the leading end part 22) of thefront portion of the base plate 12 is projected and inserted into aninterior of the lower protruding portion 48 while the upper surface ofthe rear end of the rear portion 16 of the base plate 12 is held incontact with the lower surface of a radiator support 60 that is fixedlyprovided at a front portion of the vehicle so as to extend in thevehicle width direction, for supporting a radiator 54.

In a state in which the leg-sweep apparatus 10 is thus disposed, thefirst bend 26 which is the lower end of the first vertically extendingportion 34 and which is the front end of the first horizontallyextending portion 32 is located adjacent to a lower portion of the innersurface of the lower protruding portion 48 while the third bend 30 whichis the lower end of the second vertically extending portion 38 and whichis the front end of the second horizontally extending portion 36 islocated adjacent to a middle portion of the inner surface of the lowerprotruding portion 48 in its height direction. Further, the load-inputsurfaces 42, 43 of the respective first and second vertically extendingportions 34, 38 are respectively opposed to and located as close aspossible to the lower portion and the middle portion of the innersurface of the lower protruding portion 48 in the height directionthereof.

Fixing bolts 61 are respectively inserted into the plurality ofinsertion holes 23 formed at the rear end of the rear portion 16 of thebase plate 12 and screwed into the radiator support 60, whereby the rearportion 16 of the base plate 12 is fixed to the radiator support 60.

Thus, the leg-sweep apparatus 10 is disposed in the lower part of thefront face of the vehicle such that the leg-sweep apparatus 10 ishorizontally located inside of the lower protruding portion 48 of thebumper cover 50 so as to extend in the frontward and backward directionof the vehicle, with the staircase-like portion 40 of the front portion14 of the base plate 12 projected from the front face of the vehicle andwith the rear portion 16 fixed to the radiator support 60.

In the exemplary embodiment, when a leg portion 62 of the pedestriancomes into contact or collides with the bumper cover 50 of the frontbumper 44 as indicated by a two-dot chain line in FIG. 3, the upperprotruding portion 46 and the lower protruding portion 48 of the bumpercover 50 are respectively brought into contact with the vicinity of aknee 64 and the vicinity of a shank 66 of the leg portion 62 of thepedestrian. In this instance, since the rigidity of the impact-absorbingmember 56 is made smaller than that of the leg-sweep apparatus 10, theimpact-absorbing member 56 is deformed more easily in a larger amountthan the leg-sweep apparatus 10. Accordingly, the bumper cover 50 isdeformed such that lower protruding portion 48 projects frontward of thevehicle farther than the upper protruding portion 46, so that thecounterforce with respect to the impact load generated in the leg-sweepapparatus 10 by the collision of the leg portion 62 against the bumpercover 50 acts on the vicinity of the shank 66 of the leg portion 62 ofthe pedestrian via the lower protruding portion 48 of the bumper cover50. As a result, the vicinity of the shank 66 of the leg portion 62 ofthe pedestrian is swept or scooped up by the leg-sweep apparatus 10,thereby causing the pedestrian to fall down or to be thrown toward thebonnet 52 of the vehicle. Thus, it is possible to limit bending of theknee 64 of the pedestrian in an unnatural or undesirable direction,thereby minimizing occurrence of injuries to the knee 64 such as bonefractures and effectively assuring protection and safety of thepedestrian.

In the leg-sweep apparatus 10 according to the exemplary embodiment, inparticular, the load-input surface 42 of the first vertically extendingportion 34 and the load-input surface 43 of the second verticallyextending portion 38 are located inside of the lower protruding portion48 of the bumper cover 50 so as to be opposed to and located as close aspossible to the inner surface of the lower protruding portion 48 in thefrontward and backward direction, thereby effectively reducing aclearance between the inner surface of the lower protruding portion 48of the bumper cover 50 and the front portion 14 of the base plate 12.

Each of the load-input surfaces 42, 43 is disposed so as to beright-angled to the horizontal plane that includes the input directionof the impact load, whereby the impact load is inputted, at rightangles, to the load-input surfaces 42, 43 of the respective first andsecond vertically extending portions 34, 38. Therefore, in spite of thefact that the lower protruding portion 48 of the bumper cover 50 withwhich the leg portion 62 of the pedestrian is brought into collision hasthe convex curved surface configuration in vertical cross section, thefront portion 14 of the base plate 12 is advantageously prevented frombeing deformed to be rolled up, for instance, by the impact loadinputted to the staircase-like portion 40 of the base plate 12. Thearrangement is effective to eliminate or restrain the delay of the riseof the impact load in the load characteristics.

Further, the first horizontally extending portion 32 and the secondhorizontally extending portion 36 are disposed inside of the lowerprotruding portion 48 of the bumper cover 50 so as to be located at themutually different height levels, so that the portion of the base plate12 that horizontally extends is divided into segments, so that momentarm is advantageously shortened, thereby effectively reducing rotationforce generated in the base plate 12 upon inputting of the impact load.Therefore, it is possible to advantageously prevent the front portion 14of the base plate 12 from being deformed to be rolled up, resulting in aprompt rise of the impact load in the load characteristics.

Moreover, because the first and second horizontally extending portions32, 36 disposed inside of the lower protruding portion 48 of the bumpercover 50 so as to be located at the mutually different height positionsexhibit sufficient rigidity with respect to the load inputted in thehorizontal direction, the counterforce with respect to the impact loadcan be sufficiently and reliably exhibit in the leg-sweep apparatus 10at the two different height positions upon inputting of the impact loadaccompanied by the collision of the leg portion 62 of the pedestrian.

Each of the load-input surfaces 42, 43 to which the impact load isinputted is configured to be right-angled to the horizontal plane asmentioned above, thereby advantageously increasing the contact area ofthe front portion 14 of the base plate 12 with the leg portion 62 of thepedestrian. Therefore, the impact load can be more sufficiently andreliably inputted to the leg-sweep apparatus 10. Consequently, thecounterforce with respect to the impact load can be exhibited in theleg-sweep apparatus 10 with a larger magnitude.

Accordingly, in the thus constructed leg-sweep apparatus 10, thecounterforce with respect to the impact load accompanied by thecollision of the leg portion 62 of the pedestrian against the bumpercover 50 can instantaneously act on the vicinity of the shank 66 of theleg portion 62 with a sufficiently large magnitude even when theleg-sweep apparatus 10 is disposed inside of the lower protrudingportion 48 of the bumper cover 50 whose vertical cross sectional shapeis the convex curved configuration protruding frontward. Therefore, theleg portion 62 of the pedestrian which has collided with the bumpercover 50 can be promptly and reliably swept, so that the leg portion 62of the pedestrian can be advantageously protected with high reliability.

Because the leg-sweep apparatus 10 according to the exemplary embodimentpermits a prompt rise of the impact load in the load characteristics,the impact load reaches a target value quickly. Accordingly, the presentleg-sweep apparatus 10 effectively assures a sufficient amount of theimpact-absorbing stroke accompanied by buckling deformation of thehorizontally extending portions after the impact load in the loadcharacteristics has reached the target value.

In the present leg-sweep apparatus 10 constructed as described above,the second horizontally extending portion 36 is located at the front endportion of the staircase-like portion 40 of the base plate 12 while thethird bend 30 as the front end of the second horizontally extendingportion 36 is located at the middle portion of the staircase-likeportion 40 in the height direction thereof. The thus constructedleg-sweep apparatus 10 is disposed inside of the lower protrudingportion 48 of the bumper cover 50 with the third bend 30 located at themiddle of the lower protruding portion 48 in its height direction.According to the arrangement, a point of initial contact of theleg-sweep apparatus 10 with the leg portion 62 of the pedestrian whichis brought into collision with the bumper cover 50 is the third bend 30of the staircase-like portion 40, so that the impact load can beinputted, with high reliability in the horizontal direction, to thesecond horizontally extending portion 36, whereby the front portion 14of the base plate 12 is more effectively prevented from being deformedto be rolled up. In consequence, the leg portion 62 of the pedestriancan be protected with high efficiency and high reliability.

In the exemplary embodiment, the first and second reinforcing ribs 18,20 for reinforcing the rigidity of the front portion 14 of the baseplate 12 are formed integrally with the posterior surfaces (the backsurfaces) of the load-input surfaces 42, 43 of the respective first andsecond vertically extending portions 34, 38 and the upper surfaces ofthe respective first and second horizontally extending portions 32, 36.According to the arrangement, the rigidity of the extending portions32-38 can be advantageously increased, permitting the leg-sweepapparatus 10 to sufficiently exhibit the counterforce with respect tothe impact load. As a result, the leg-sweep apparatus 10 assures furtherenhanced performance of protecting the leg portion 62 of the pedestrian.Moreover, by adjusting the number of the first and second reinforcingribs 18, 20 and the locations of the same 18, 20, it is possible tosuitably change the rigidity of the front portion 14 of the base plate12, whereby the amount of buckling deformation of the front portion 14of the base plate 12 accompanied by the input of the impact load can beeasily tuned depending upon the magnitude of the impact load to beinputted.

In the exemplary first embodiment, the forward end of the staircase-likeportion 40 of the base plate 12 is constituted by the second verticallyextending portion 38 that extends straightly in the vertical direction.The forward end of the staircase-like portion 40 may be constituted by ahorizontally extending portion that extends horizontally, as shown inthe leg-sweep apparatus of FIG. 4 constructed according to a secondembodiment of the invention. In the second embodiment, the samereference numerals as used in the illustrated first embodiment of FIGS.1-3 are used to identify the corresponding components, and a detailedexplanation of which is dispensed with.

In the leg-sweep apparatus 10 according to the exemplary secondembodiment, the leading end part 22 of the front portion 14 of the baseplate 12 is in a bent form obtained by bending a flat plate extendingstraightly in the frontward and backward direction, at right angles inthe frontward and backward direction at four locations which are spacedapart from each other by a prescribed distance in the frontward andbackward direction, whereby the leading end part 22 includes, inaddition to the first through third bends 26-30, a fourth bend 68 formedover the third bend 30. A portion of the leading end part 22 of the baseplate 12 located on the front side of the fourth bend 68 (i.e., theforward end of the leading end part 22) is bent at right angles from theupper end of the second vertically extending portion 38 and is made as athird horizontally extending portion 70 that horizontally and straightlyextends in the frontward and backward direction under installation ofthe leg-sweep apparatus 10 on the vehicle.

Thus, in the leading end part 22 of the front portion 14 of the baseplate 12, each of the first, second and third horizontally extendingportions 32, 36, 70 and each of the first and second verticallyextending portions 34, 38 are alternately disposed in the frontward andbackward direction so as to extend in a staircase-like form, whereby theentirety of the leading end part 22 is made as a staircase-like portion40 constituted by the first, second and third horizontally extendingportions 32, 36, 70 and the first and second vertically extendingportions 34, 38.

The thus constructed leg-sweep apparatus 10 having the staircase-likeportion 40 in which the third horizontally extending portion 70 isadditionally provided is disposed at the lower part of the front face ofthe vehicle so as to be located inside of the lower protruding portion48 of the bumper cover 50, such that the rear portion 16 is fixed to theradiator support 60 by the fixing bolts 61, with the staircase-likeportion 40 (the leading end part 22) of the front portion 14 of the baseplate 12 inserted into the interior of the lower protruding portion 48.

With the leg-sweep apparatus 10 installed on the vehicle as describedabove, in particular, the third horizontally extending portion 70horizontally extends toward the inner surface of the lower protrudingportion 48 so as to minimize a clearance formed between the front endface of the third horizontally extending portion 70 of thestaircase-like portion 40 inserted into the interior of the lowerprotruding portion 48 and the inner surface of the lower protrudingportion 48.

Accordingly, when the leg-sweep apparatus 10 constructed as describedabove is disposed inside of the lower protruding portion 48 of thebumper cover 50 having, in the vertical cross section, the convex curvedsurface configuration protruding forward, the clearance formed betweenthe lower protruding portion 48 and the base plate 12 is advantageouslymade small, thereby effectively assuring a prompt rise of the impactload in the load characteristics, so that the leg portion of thepedestrian can be protected with higher reliability.

In addition, the vertically extending portion 34 extends straightly inthe vertical direction of the vehicle, so that the impact load that isimposed upon frontal collision can be received by a plane of thevertically extending portion 34, in the horizontal direction.Accordingly, the vertically extending portion 34 can withstand a higherload, whereby a leg portion of the pedestrian can surely be swept.

It is noted that the respective numbers, the respective dimensions ofextension, etc., of the horizontally extending portions 32, 36, 70 andthe vertically extending portions 34, 38 that constitute thestaircase-like portion 40 are not limited to those in the illustratedfirst and second embodiments, but may be suitably determined dependingupon the desired pedestrian protection performance, more specifically,the magnitude of the counterforce to be exhibited in the pedestrianprotection apparatus, the installation space for the pedestrianprotection apparatus and the like.

In the illustrated first and second embodiments, in the leading end part22 of the front portion 14 of the base plate 12, the portion thereoflocated on the back side of the first vertically extending portion 34 ismade as the first horizontally extending portion 32, and the entirety ofthe leading end part 22 including the first horizontally extendingportion 32 is formed as the staircase-like portion 40. Thestaircase-like portion 40 may be formed by the leading end part 22 thatexcludes the first horizontally extending portion 32. Namely, a portionof the leading end part 22 of the front portion 14 of the base plate 12may be formed as the staircase-like portion 40. In this case, thestaircase-like portion 40 in the illustrated first embodiment isconstituted by the first and second vertically extending portions 34, 38and the second horizontally extending portion 36 while thestaircase-like portion 40 in the illustrated second embodiment isconstituted by the first and second vertically extending portions 34, 38and the second and third horizontally extending portions 36, 70.

The installation structure of the pedestrian protection apparatus (theleg-sweep apparatus 10) on the lower part of the front face of thevehicle is not particularly limited. Namely, the portion of the vehicleto which the rear portion of the plate member (the base plate 12) isfixed and the manner of fixing may be variously changed. Further, thepedestrian protection apparatus may be disposed at the lower part of thevehicle separately from and independently of the front bumper.

In the illustrated first and second embodiments, among the at least onehorizontally extending portion 32, 36 and the plurality of verticallyextending portions 34, 38, those which are located nearer to the forwardend of the leading end part 22 are disposed at higher levels, wherebythe staircase-like portion 40 is formed in a rising or ascendingconfiguration in the frontward direction. On the contrary, among the atleast one horizontally extending portion 32, 36 and the plurality ofvertically extending portions 34, 38, those which are located nearer tothe forward end of the leading end part 22 may be disposed at lowerlevels, whereby the staircase-like portion 40 is formed in a descendingconfiguration in the frontward direction, further in a configurationascending or descending in the backward direction from a bent state inwhich the leading end part 22 is bent backward.

Each of the anterior surfaces of the vertically extending portions inthe staircase-like portion may be constituted by a flat plane orthogonalto the horizontal plane.

The configuration, the location, the number, etc., of the reinforcingribs provided on the plate member are not particularly limited. Thereinforcing ribs are not indispensable in the present invention, and maybe eliminated.

Referring next to the plan view of FIG. 5 and the vertical crosssectional view of FIG. 6, the leg-sweep apparatus as the pedestrianprotection apparatus constructed according to a third embodiment of theinvention will be explained. In the third embodiment, the same referencenumerals as used in the illustrated first and second embodiments areused to identify the corresponding components, and a detailedexplanation of which is not given.

As in the illustrated first and second embodiments, the base plate 12 asthe plate portion is formed of the synthetic resin material such aspolypropylene or ABS resin. Namely, the base plate 12 is constituted bya thin planar plate having a generally rectangular shape. In the baseplate 12, the dimension as measured in a vertical direction of FIG. 5,i.e., the dimension as measured in the vehicle width direction or theleftward and rightward (lateral) direction of the vehicle underinstallation of the leg-sweep apparatus 10 on the vehicle, is madesmaller than the vehicle width by a suitable amount, and the dimensionas measured in a transverse direction of FIG. 5, i.e., the dimension asmeasured in the frontward and backward direction of the vehicle, is madesufficiently smaller the above-indicated direction as measured in theleftward and rightward direction.

As in the illustrated first and second embodiments, the base plate 12includes the front portion 14 and the rear portion 16. At the rear endof the rear portion 16, the plurality of insertion holes 23 (here, fiveinsertion holes 23) are formed through the thickness thereof into whichsuitable fixing bolts or the like are insertable, such that theinsertion holes 23 are spaced apart from each other by a prescribeddistance in the leftward and rightward direction.

In the leg-sweep apparatus 10 constructed according to the exemplarythird embodiment, the front portion 14 of the base plate 12 has aspecial structure not found in conventional apparatus.

Namely, at a leading end part 120 of the front portion 14 of the baseplate 12, there are provided three vertically extending portions 122,124, 126 which extend straightly in the vertical direction over theentire width of the base plate 12 such that those vertically extendingportions 122, 124, 126 are opposed to and spaced apart from each otherby a constant distance in the frontward and backward direction. Inaddition, there are provided two horizontally extending portions 128,130 which extend straightly in the horizontal direction over the entirewidth of the base plate 12 such that the horizontally extending portion128 is interposed between the two vertically extending portions 122, 124while the horizontally extending portion 130 is interposed between thetwo vertically extending portions 124,126.

More specifically described, the three vertically extending portions122, 124, 126 consist of: a front-side vertically extending portion 122which is located at the forward end of the front portion 14 of the baseplate 12; a first rear-side vertically extending portion 124 which islocated immediately on the back side of the front-side verticallyextending portion 122 so as to be opposed thereto; and a secondrear-side vertically extending portion 126 which is located on the backside of the first rear-side vertically extending portion 124 so as to beopposed thereto at a substantially middle of the front portion 14 asseen in the frontward and backward direction. Each of the front-side,first rear-side and second rear-side vertically extending portions 122,124, 126 has the same width as that of the base plate 12, and the sameheight (the dimension in the vertical direction) with each other. Eachvertically extending portion 122, 124, 126 is constituted by a thin flatplate having a curved configuration that is deflected or warped so as tobe convexed frontward in the thickness direction thereof.

According to the arrangement, the front end surface of the base plate12, i.e., a load-input surface 131 to which the impact load generatedupon collision of the leg portion of the pedestrian against the frontface of the vehicle is inputted is constituted by an anterior surface132 of the front-side vertically extending portion 122. The load-inputsurface 131 given by the anterior surface 132 is made as a curvedsurface obtained by deflecting or warping a vertical plane which isright-angled with respect to a horizontal plane that includes the inputdirection of the impact load generated accompanied by the collision ofthe leg portion of the pedestrian against the front face of the vehicle,such that the vertical plane is gradually curved backward from themiddle portion thereof as seen in the leftward and rightward directiontoward the opposite end portions thereof as seen in the same direction.Namely, the load-input surface 131 is constituted as a convex curvedsurface protruding frontward and formed by a path that is obtained bymoving a vertical line so as to draw an arc.

In the meantime, the horizontally extending portions 128, 130 consistof: a front-side horizontally extending portion 128 which is locatedbetween the lower ends of the respective front-side and first rear-sidevertically extending portion 122, 124; and a rear-side horizontallyextending portion 130 which is located between the upper ends of therespective first and second rear-side vertically extending portions 124,126. Each of the front-side and rear-side horizontally extendingportions 128, 130 is constituted by a thin flat plate which has a curvedconvex configuration protruding frontward in the width direction andcorresponding to the anterior and posterior surfaces of the respectivevertically extending portions 122, 124, 126 and which has a length(i.e., a dimension as measured in the leftward and rightward direction)that is the same as the width of the base plate 12 and a width (i.e., adimension as measured in the frontward and backward direction) that isthe same as a distance between any adjacent two of the verticallyextending portions 122, 124, 126 which are opposed to each other.

The lower ends of the respective front-side vertically extending portion122 and first rear-side vertically extending portions 124 are connectedintegrally to each other by the front-side horizontally extendingportion 128 while the upper ends of the respective first and secondrear-side vertically extending portions 124, 126 are connectedintegrally to each other by the rear-side horizontally extending portion130. The second rear-side vertically extending portion 126 is connected,at its lower end, integrally to the rear portion 16 of the base plate 12by a connecting portion 135 which is given by a proximal end part 134 ofthe front portion 14 of the base plate 12.

Thus, the front-side vertically extending portion 122, the firstrear-side vertically extending portion 124 and the second rear-sidevertically extending portion 126 are formed integrally on the frontportion 14 of the base plate 12 so as to extend therefrom, such thatadjacent two of the vertically extending portions 122, 124, 126 that areopposed to each other are connected integrally to each other by acorresponding one of the front-side and rear-side horizontally extendingportions 128, 130 that are located at mutually different height levelsin the frontward and backward direction.

In other words, in the leg-sweep apparatus 10 according to the exemplarythird embodiment, the leading end part 120 of the front portion 14 ofthe base plate 12 is in a bent form obtained by bending a flat plateextending straightly in the frontward and backward direction, at rightangles at its five locations which are spaced apart from each other by aprescribed distance in the frontward and rightward direction, so as toprovide a first bend 136, a second bend 138, a third bend 140, a fourthbend 142 and a fifth bend 144 in order as seen from the front side.

In the leading end part 120 described above, a portion between the fifthbend 144 located at the rearmost of the leading end part 120 and thefourth bend 142 located on the front side of the fifth bend 144 is madeas the second rear-side vertically extending portion 126 that extendsstraightly in the vertically upward direction from the front end of theconnecting portion 135 as the proximal end part 134 of the front portion14 of the base plate 12. A portion of the leading end part 120 betweenthe fourth bend 142 and the third bend 140 which is located on the frontside of the fourth bend 142 is made as the rear-side horizontallyextending portion 130 that extends straightly in the horizontallyforward direction from the upper end of the second rear-side verticallyextending portion 126. A portion of the leading end part 120 between thethird bend 140 and the second bend 138 which is located on the frontside of the third bend 140 is made as the first rear-side verticallyextending portion 124 that extends straightly in the vertically downwarddirection from the front end of the rear-side horizontally extendingportion 130. A portion of the leading end part 120 between the secondbend 138 and the first bend 136 which is located on the front side ofthe second bend 138 is made as the front-side horizontally extendingportion 128 that extends straightly in the horizontally frontwarddirection from the lower end of the first rear-side vertically extendingportion 124. An entire portion located on the front side of the firstbend 136 is made as the front-side vertically extending portion 122 thatextends straightly in the vertically upward direction from the front endof the front-side horizontally extending portion 128.

Thus, the leading end part 120 of the front portion 14 of the base plate12 is constituted by the front-side vertically extending portion 122,the front-side horizontally extending portion 128, the first rear-sidevertically extending portion 124, the rear-side horizontally extendingportion 130 and the second rear-side vertically extending portion 126,so as to extend in the frontward and backward direction in a zigzag formin the upward and downward direction with a U-shaped configuration invertical cross section.

In the arrangement described above, there is formed, at the front of theleading end part 120 of the base plate 12, a front-side U-shaped portion146 that is constituted by the front-side horizontally extending portion128, and the front-side vertically extending portion 122 and the firstrear-side vertically extending portion 126 which are respectively formedintegrally to the front end and the rear end of the front-sidehorizontally extending portion 128 such that the vertically extendingportions 122, 126 are opposed to each other and extend straightly in thevertically upward direction. The front-side U-shaped portion 146 has aU-shaped configuration in vertical cross section that is open upward andextends over the entire width of the base plate 12. Further, there isformed, at the back of the leading end part 120, a rear-side U-shapedportion 148 that is constituted by the rear-side horizontally extendingportion 130, and the first and second rear-side vertically extendingportions 124, 126 which are respectively formed integrally to the frontend and the rear end of the rear-side horizontally extending portion 130such that the vertically extending portions 124, 126 are opposed to eachother and extend straightly in the vertically downward direction. Therear-side U-shaped portion 148 has a U-shaped configuration in verticalcross section that is open downward and extends over the entire width ofthe base plate 12. That is, the front-side U-shaped portion 146 and therear-side U-shaped portion 148 are formed integrally on the leading endpart 120 of the front portion 14 of the base plate 12 so as to belocated continuously in the frontward and backward direction.

Accordingly, in the present leg-sweep apparatus 10, the front-sideU-shaped portion 146 and the rear-side U-shaped portion 148 provided onthe leading end part 120 of the front portion 14 of the base plate 12function as beads which reinforce the front portion 14 (the leading endpart 120), thereby increasing the flexural or bending strength of thefront portion 14. Thus, the rigidity with respect to the impact load tobe inputted upon collision of the leg portion of the pedestrian againstthe front face of the vehicle can be sufficiently obtained, as describedbelow.

Further, on the front portion 14 of the base plate 12, there are formed,each as a reinforcing portion, first through third reinforcing ribs 150,152, 154 which are formed integrally to the upper surface of thefront-side horizontally extending portion 128, the lower surface of therear-side horizontally extending portion 130 and the upper surface ofthe connecting portion 135 which is given by the proximal end part 134.

Namely, each of the first reinforcing ribs 150 is a flat plate havingthe same height as the front-side vertically extending portion 122 andthe first and second rear-side vertically extending portions 124, 126and the thickness smaller than the thickness of those verticallyextending portions 122,124, 126. The first reinforcing ribs 150 areopposed to and spaced apart from each other in the leftward andrightward direction by a suitable distance so as to be parallel to eachother. The thus located first reinforcing ribs 150 extend continuouslyand straightly in the frontward and backward direction so as to beintegral with the posterior surface of the front-side verticallyextending portion 122 and the anterior surface of the first rear-sidevertically extending portion 124.

Each of the second reinforcing ribs 152 is a flat plate having a height,a thickness and a length (i.e., a dimension as measured in the frontwardand backward direction) which are the same as those of the firstreinforcing ribs 150. The number of the second reinforcing ribs 152 isthe same as that of the first reinforcing ribs 150. The secondreinforcing ribs 152 are located between the first-side and second-sidevertically extending portions 124, 126 such that the second reinforcingribs 152 are opposed to and spaced apart from each other in the leftwardand rightward direction by the same distance as the distance between anyadjacent two of the first reinforcing ribs 150, so as to be parallel toeach other. The thus located second reinforcing ribs 152 extendcontinuously and straightly in the frontward and backward direction soas to be integral with the posterior surface of the first rear-sidevertically extending portion 124 and the anterior surface of the secondrear-side vertically extending portion 126. The location of each of thesecond reinforcing ribs 152 in the leftward and rightward directioncorresponds to the location of each of the first reinforcing ribs 150 inthe same direction.

While each of the third reinforcing ribs 154 has a height and athickness which are the same as those of the first and secondreinforcing ribs 150, 152, each third reinforcing rib 154 has a length(i.e., a dimension as measured in the frontward and backward direction)which is larger than that of the first and second reinforcing ribs 150,152. The number of the third reinforcing ribs 154 is approximately halfthe number of the first and second reinforcing ribs 150, 152. The thirdreinforcing ribs 154 are located on the back side of the secondrear-side vertically extending portion 126 such that the thirdreinforcing ribs 154 are opposed to and spaced apart from each other inthe leftward and rightward direction by a distance twice the distancebetween any adjacent two of the first reinforcing ribs 150, so as to beparallel to each other. The thus located third reinforcing ribs 154 areintegral with the posterior surface of the second rear-side verticallyextending portion 126 and extend continuously and straightly in thefrontward and backward direction from the posterior surface of thesecond rear-side vertically extending portion 26 to a boundary betweenthe front portion 14 and the rear portion 16.

As explained above, the first and second reinforcing ribs 150, 152 areformed, at close intervals, integrally with the leading end part 120 ofthe front portion 14 of the base plate 12 on which are formed thefront-side U-shaped portion 146 and the rear-side U-shaped portion 148,thereby sufficiently increasing the flexural or bending strength of theleading end part 120, further, the rigidity of the same 120 with respectto the impact load. Moreover, the third reinforcing ribs 154 are formedintegrally with the proximal end portion 134 (the connecting portion135) of the front portion 14, whereby the proximal end part 134advantageously has increased flexural or bending strength, further,increased rigidity with respect to the impact load, as compared with acase in which the rear portion 16 of the base plate 12 has noreinforcing ribs 154.

As shown in FIG. 7, the leg-sweep apparatus 10 is installed inside ofthe front bumper 44 which has a structure similar to that explainedabove with respect to the illustrated first exemplary embodiment.

As in the illustrated first embodiment, the impact-absorbing member 56whose rigidity is smaller than that of the leg-sweep apparatus 10 isfixed, inside of the upper protruding portion 46 of the bumper cover 50,to the bumper reinforcement 58 as the rigid member.

The leg-sweep apparatus 10 is disposed inside of the front bumper 44 asdescribed below: The front-side and rear-side U-shaped portions 146, 148formed at the leading end part 120 of the front portion 14 of the baseplate 12 are projected from the front face of the vehicle, and the frontof the front-side U-shaped portion 146 is inserted into the interior ofthe lower protruding portion 48 while the upper surface of the rear endof the rear portion 16 of the base plate 12 is held in contact with thelower surface of the radiator support 60 that is fixedly provided at thefront portion of the vehicle so as to extend in the vehicle widthdirection, for supporting the radiator 54. The fixing bolts 61 arerespectively inserted into the plurality of insertion holes 23 formed atthe rear end of the rear portion 16 of the base plate 12 and screwedinto the radiator support 60, whereby the rear portion 16 of the baseplate 12 is fixed to the radiator support 60.

Thus, the leg-sweep apparatus 10 is disposed in the lower part of thefront face of the vehicle so as to extend horizontally in the frontwardand backward direction and is fixedly positioned such that theload-input surface 131 of the front-side vertically extending portion122 in the front-side U-shaped portion 146 of the base plate 12 isopposed to the inner surface of the lower protruding portion 48 of thebumper cover 50 and such that the first bend 36 which is the lower endof the front-side vertically extending portion 122 and which is thefront end of the front-side horizontally extending portion 128 islocated adjacent to the inner surface of the lower protruding portion 48of the bumper cover 50.

As described above with respect to the illustrated first embodiment, inthe exemplary third embodiment, when the leg portion 62 of thepedestrian comes into contact or collides with the bumper cover 50 ofthe front bumper 44 as shown in FIG. 8, the upper protruding portion 46and the lower protruding portion 48 of the bumper cover 50 arerespectively brought into contact with the vicinity of the knee 64 andthe vicinity of the shank 66 of the leg portion 62 of the pedestrian. Inthis instance, since the rigidity of the impact-absorbing member 56 ismade smaller than that of the leg-sweep apparatus 10, theimpact-absorbing member 56 is deformed more easily in a larger amountthan the leg-sweep apparatus 10. Accordingly, the bumper cover 50 isdeformed such that lower protruding portion 48 projects frontward of thevehicle farther than the upper protruding portion 46, so that thecounterforce with respect to the impact load generated in the leg-sweepapparatus 10 by the collision of the leg portion 62 against the bumpercover 50 acts on the vicinity of the shank 66 of the leg portion 62 ofthe pedestrian via the lower protruding portion 48 of the bumper cover50. As a result, the vicinity of the shank 66 of the leg portion 62 ofthe pedestrian is swept or scooped up by the leg-sweep apparatus 10,thereby causing the pedestrian to fall down or to be thrown toward thebonnet 52 of the vehicle. Thus, it is possible to limit bending of theknee 64 of the pedestrian in an unnatural or undesirable direction,thereby minimizing occurrence of injuries to the knee 64 such as bonefractures and effectively assuring protection and safety of thepedestrian.

In particular, the leg-sweep apparatus 10 constructed as described abovehas, at the leading end part 120 of the front portion 14 of the baseplate 12, the front-side U-shaped portion 146 and the rear-side U-shapedportion 148 each functioning as a bead for reinforcing the leading endpart 120. In addition, the first through third reinforcing ribs 150-154are formed integrally with the leading end part 120 and the proximal endpart 134, whereby the rigidity of the front portion 14 as a whole withrespect to the impact load is sufficiently obtained. Therefore, thefront portion 14 of the base plate 12 is effectively prevented frombeing easily deformed or deflected due to the impact load inputtedthereto.

In the leg-sweep apparatus 10 constructed as described above, theload-input surface 131 of the front-side vertically extending portion122 which is located so as to be opposed to the inner surface of thelower protruding portion 48 of the bumper cover 50 is orthogonal to thehorizontal plane that includes the input direction of the impact load,whereby the impact load is inputted perpendicularly to the load-inputsurface 131. Accordingly, the front portion 14 of the base plate 12 canbe advantageously prevented from being easily deformed or deflected.

Further, the front-side and rear-side horizontally extending portions128, 130 of the respective front-side and rear-side U-shaped portions146, 148 are located at mutually different height levels. Accordingly,the portion of the base plate 12 that horizontally extends is dividedinto: a continuous portion between the proximal end portion 134 of thefront portion 14 and the rear portion 16; the front-side horizontallyextending portion 128; and the rear-side horizontally extending portion130. Accordingly, the moment arm can be advantageously shortened, andthe rotation force generated in the base plate 12 upon inputting of theimpact load is effectively weakened, thereby assuring the effect ofpreventing easy deformation or deflection of the front portion 14 of thebase plate 12.

In the leg-sweep apparatus 10 constructed as described above accordingto the third exemplary embodiment, the front-side U-shaped portion 146and the rear-side U-shaped portion 148 are formed continuously, so thatthe leading end part 120 of the front portion 14 of the base plate 12has, as a whole, a zigzag configuration shown in FIG. 6 extending in thefrontward and backward direction. Accordingly, as shown in FIG. 7, dueto the impact load inputted to the front-side vertically extendingportion 122 of the front-side U-shaped portion 146, the front-side andrear-side horizontally extending portions 128, 130 of the respectivefront-side and rear-side U-shaped portions 146, 148 are displacedbackward while the impact load is gradually transmitted from the frontportion 14 toward the rear portion 16 of the base plate 12. In thisinstance, the first and second rear-side vertically extending portions124, 126 of the respective front-side and rear-side U-shaped portion146, 148 are deformed over a wide range in the width direction of thebase plate 12, such that those vertically extending portions 124, 126incline frontward or backward by a suitable angle with respect to thevertical direction. Therefore, the impact load is effectivelytransmitted in the width direction of the base plate 12. Consequently,the impact load is advantageously distributed in the front portion 14 ofthe base plate 12, whereby the front portion 14 of the base plate 12 iseffectively prevented from easily deformed or deflected upon inputtingof the impact load thereto.

As explained above, in the present embodiment, the easy deformation ordeflection of the front portion 14 of the base plate 12 upon inputtingof the impact load thereto can be prevented, thereby obviating a delayof rise of the impact load in the load characteristics due todeformation or deflection of the front portion 14 of the base plate 12.

Accordingly, the present leg-sweep apparatus 10 permits a prompt rise ofthe impact load in the load characteristics, whereby sufficientcounterforce with respect to the impact load can be instantaneously andadequately exhibited. As a result, the leg portion 62 of the pedestrianwhich has collided with the front bumper 44 can be instantaneously andreliably swept, assuring a higher level of protection of the leg portion62 of the pedestrian.

Since the present leg-sweep apparatus 10 permits a prompt rise of theimpact load in the load characteristics, the impact load can reach atarget value more quickly. Consequently, the present leg-sweep apparatus10 effectively assures a sufficient amount of the impact-absorbingstroke accompanied by buckling deformation off the horizontallyextending portions 128, 130, the connecting portion 135, etc., after theimpact load in the load characteristics has reached the target value.

In the exemplary third embodiment, the first through third reinforcingribs 150-154 are formed integrally with the front portion 14 of the baseplate 12 for increasing the rigidity of the same 14. As compared with anarrangement in which the rigidity of the front portion 14 is increasedby securing, to the base plate 12, members separate from the base plate12, for instance, the present arrangement is effective to improve themanufacturing efficiency and lower the manufacturing cost of the baseplate 12, and accordingly the leg-sweep apparatus 10 as a whole.Moreover, by adjusting the number, the location, etc., of each of thefirst through third reinforcing ribs 150-154, the rigidity of the frontportion 14 of the base plate 12 can be suitably changed, thereby makingit possible to easily tune, depending upon the magnitude of the impactload to be inputted, the amount of buckling deformation of the frontportion 14 of the base plate 12 accompanied by the input of the impactload, and accordingly the amount of absorption of impact energy based onthe buckling deformation of the front portion 14.

In the illustrated third embodiment, the leading end part 120 of thefront portion 14 of the base plate 12 is provided with the two U-shapedportions 146, 148 which are continuously formed thereon. The leading endpart 120 may have only one U-shaped portion 84, as shown in theleg-sweep apparatus of FIG. 9 according to a fourth embodiment of theinvention. In the fourth embodiment, the same reference numerals as usedin the embodiments illustrated above are used to identify thecorresponding components, and a detailed explanation of which isomitted.

In the leg-sweep apparatus 10 according to the fourth embodiment shownin FIG. 9, a front-side vertically extending portion 86 and a rear-sidevertically extending portion 88 which straightly extend in the verticaldirection over the entire width of the base plate 12 are integrallyformed on the leading end part 120 of the front portion 14 of the baseplate 12, such that the vertically extending portions 86, 88 are opposedto and spaced apart from each other by a constant distance in thefrontward and backward direction. Those front-side and rear-sidevertically extending portions 86, 88 have a construction similar to thatof the front-side and rear-side vertically extending portions (22), (24)in the illustrated third embodiment.

According to the arrangement described above, the anterior surface 90 ofthe front-side vertically extending portion 86 is made as a load-inputsurface 131 constituted by a curved surface obtained by deflecting orwarping a vertical plane which is right-angled with respect to thehorizontal plane that includes the direction of input of the impact loadgenerated upon collision of the leg portion 62 of the pedestrian againstthe front bumper 44, such that the vertical plane is gradually curvedbackward from the middle portion thereof as seen in the leftward andrightward direction toward the opposite end portions thereof as seen inthe same direction. Namely, the load-input surface 131 is constituted bya convex curved surface which protrudes forward and which is formed by apath that is obtained by moving a vertical line so as to draw an arc.

Further, between the upper ends of the respective front-side andrear-side vertically extending portions 86, 88, there is located ahorizontally extending portion 94 which straightly extends in thehorizontal direction over the entire width of the base plate 12 in thefrontward and backward direction, whereby the upper ends of therespective front-side and rear-side vertically extending portions 86, 88are connected integrally to each other by the horizontally extendingportion 94. A connecting portion 135 constituted by a proximal end part134 of the front portion 14 of the base plate 12 is connected integrallyto the lower end of the posterior surface of the rear-side verticallyextending portion 88, which posterior surface is opposite to theanterior surface thereof to which the horizontally extending portion 94is connected.

In other words, in the exemplary fourth embodiment, the horizontallyextending portion 94 is located at the leading end part 120 of the frontportion 14 of the base plate 12, and the front-side vertically extendingportion 86 is formed integrally with the front end of the horizontallyextending portion 94 so as to straightly extend therefrom in thevertically downward direction. Further, the rear-side verticallyextending portion 88 is formed integrally with rear end of thehorizontally extending portion 94 such that the rear-side verticallyextending portion 88 is opposed to and spaced apart from the front-sidevertically extending portion 86 with a distance corresponding to thelength of extension of the horizontally extending portion 94 interposedtherebetween, so as to extend straightly in the vertically downwarddirection. The connecting portion 135 is connected, at its front end,integrally to the lower end of the posterior surface of the rear-sidevertically extending portion 88.

Thus, at the leading end part 120 of the front portion 14 of the baseplate 12, there is formed a U-shaped portion 84 constituted by thefront-side vertically extending portion 86, the horizontally extendingportion 94 and the rear-side vertically extending portion 88 andextending over the entire width of the base plate 12 with a U-shapedconfiguration that is open downward in vertical cross section.

In the thus constructed leg-sweep apparatus 10, the U-shaped portion 84functions as a bead for reinforcing the leading end part 120 of thefront portion 14 of the base plate 12, thereby sufficiently assuring theflexural or bending strength of the leading end part 120 and accordinglythe rigidity of the same 120 with respect to the impact load.

In addition, the horizontally extending portion 94 and the connectingportion 135 are located at mutually different height levels, so that themoment arm can be advantageously shortened, and the rotation forcegenerated in the plate member upon inputting of the impact load iseffectively weakened, thereby assuring the effect of preventing theleading end part of the plate member from being deformed to be rolledup.

On the lower surface of the horizontally extending portion 94 whichpartially constitutes the U-shaped portion 84, there are provided aplurality of front-side reinforcing ribs 96 that are similar inconstruction to the first and second reinforcing ribs (150), (152)described in the illustrated third embodiment. The reinforcing ribs 96are thin flat plates and are spaced apart from each other by a suitabledistance in the leftward and rightward direction, so as to be integralwith the posterior surface of the front-side vertically extendingportion 86 and the anterior surface of the rear-side verticallyextending portion 88. Moreover, on the upper surface of the connectingportion 135 constituted by the proximal end part 134 of the frontportion 14 of the base plate 12, there are provided a plurality ofrear-side reinforcing ribs 98 that are similar in construction to thethird reinforcing ribs (154) described in the illustrated thirdembodiment. The rear-side reinforcing ribs 98 are thin flat plates andare spaced apart from each other by a suitable distance in the leftwardand rightward direction, so as to be integral with the posterior surfaceof the rear-side vertically extending portion 88. According to thearrangement, the rigidity of the front portion 14 of the base plate 12with respect to the impact load is more efficiently enhanced.

As in the illustrated third embodiment, the thus constructed leg-sweepapparatus 10 is disposed at the lower part of the vehicle with the frontof the U-shaped portion 84 inserted and projected into the lowerprotruding portion 48 of the bumper cover 50 of the front bumper 44.

Accordingly, as the present leg-sweep apparatus 10 assures sufficientrigidity with respect to the impact load, so that the front portion 14of the base plate 12 is effectively prevented from being easilydeflected upon collision of the leg portion 62 of the pedestrian againstthe front bumper 44.

Further, when the impact load is inputted, the horizontally extendingportion 94 of the U-shaped portion 84 is displaced backyard while thefront-side and rear-side vertically extending portions 86, 88 aredeformed over a wide range in the width direction of the base plate 12so as to be inclined frontward or backward by a suitable angle withrespect to the vertical direction. Accordingly, the impact load iseffectively transmitted in both of the length direction and the widthdirection of the base plate and advantageously distributed in the frontportion 14 of the base plate 12, preventing easy deflection of the frontportion 14 of the base plate 12 due to the impact load inputted thereto.

Therefore, the leg-sweep apparatus 10 constructed as described abovepermits a prompt rise of the impact load in the load characteristics,thereby exhibiting sufficient counterforce with respect to the impactload at earlier timing. Consequently, the leg portion 62 of thepedestrian collided with the front bumper 44 can be promptly andreliably swept, so that the performance of protecting the leg portion ofthe pedestrian can be effectively enhanced.

In the leg-sweep apparatus 10 constructed as described above, only oneU-shaped portion 84 is formed at the front portion 14 of the base plate12, simplifying the structure of the base plate 12, and accordingly thestructure of the leg-sweep apparatus 10 as a whole.

Referring next to FIG. 10, there will be explained a modified structureof the leg-sweep apparatus according to a fifth embodiment of theinvention. In the exemplary fifth embodiment, while only one U-shapedportion 84 is formed at the leading end part 120 of the front portion 14of the base plate 12 as in the illustrated fourth embodiment, thefront-side vertically extending portion 86 of the U-shaped portion 84has a special structure. Further, in the exemplary fifth embodimentshown in FIG. 10, the U-shaped portion 84 has a U-shaped configurationthat is open upward. In the fifth embodiment, the same referencenumerals as used in the illustrated embodiments are used to identify thecorresponding components, and a detailed explanation of which isdispensed with.

In the leg-sweep apparatus 10 shown in FIG. 10, the front-sidevertically extending portion 86 is bent at right angles at two locationsin its height direction, so as to extend frontward in a staircase-likeform.

In other words, front-side vertically extending portion 86 is dividedinto an upper front-side vertically extending portion 100 and a lowerfront-side vertically extending portion 102 which have mutually the sameheight dimension. The upper front-side vertically extending portion 100and the lower front-side vertically extending portion 102 are positionedat mutually different height levels such that the former 100 is locatedfrontward of the latter 102. These upper and lower front-side verticallyextending portions 100, 102 are connected integrally to each other by anintermediate horizontally extending portion 104 that extendshorizontally in the frontward and backward direction between the lowerend of the upper front-side vertically extending portion 100 and theupper end of the lower front-side vertically extending portion 102.

According to the arrangement, the front of the U-shaped portion 84provided at the leading end part 120 of the front portion 14 of the baseplate 12 is constituted as a staircase-like portion, and an anteriorsurface 106 of the upper front-side vertically extending portion 100 ofthe staircase-like portion is made as the load-input surface 131 thatstraightly extends in the vertical direction. A horizontal projection108 projecting in the horizontal direction by a prescribed amount isformed integrally with the load-input surface 131. The horizontalprojection 108 is a rib formed of a thin, flat plate having the samethickness as that of the upper and lower front-side vertically extendingportions 100, 102.

In the present leg-sweep apparatus 10 constructed as described above,the entirety of the front portion 14 of the base plate 12 except for theleading end part 120 on which is formed the U-shaped portion 84 is madeas the proximal end part 134. The proximal end part 134 is made as theconnecting portion 135 which connects the rear-side vertically extendingportion 88 of the U-shaped portion 84 and the rear portion 16 of thebase plate 12 integrally to each other. The connecting portion 135consists of: a rear part which extends horizontally and frontward fromthe rear portion 16 of the base plate; an intermediate part whichextends frontward and obliquely upward from the front end of the rearpart; and a front part which extends horizontally and frontward from thefront of the intermediate part and which is connected integrally to amiddle portion of the posterior surface of the rear-side verticallyextending portion 88 of the U-shaped portion 84 in the height directionthereof.

On the thus constructed front portion 14 of the base plate 12, there areformed a plurality of front-side reinforcing ribs 96 and a plurality ofrear-side reinforcing ribs 98 each of which is a thin flat plate, as inthe illustrated fourth embodiment. Here, the front-side reinforcing ribs96 consist of: a plurality of upper front-side reinforcing ribs 96 awhich are formed on the upper surface of the horizontally extendingportion 94 of the U-shaped portion 84 and which are integral with theposterior surfaces of the respective upper and lower front-sidevertically extending portions 100, 102, the upper surface of theintermediate horizontally extending portion 104 and the anterior surfaceof the rear-side vertically extending portion 88; and a plurality oflower front-side reinforcing ribs 96 b which are formed on the lowersurface of the intermediate horizontally extending portion 104 of theU-shaped portion 84 and the lower surface of the horizontal projection108 and which are integral with the anterior surface of the lowerfront-side vertically extending portion 102. Each of the lowerfront-side reinforcing ribs 96 b has a triangular shape. The rear-sidereinforcing ribs 98 consist of: a plurality of upper rear-sidereinforcing ribs 98 a which are formed on the upper surface of theconnecting portion 135 and which are integral with the upper part of theposterior surface of the rear-side vertically extending portion 88; anda plurality of lower rear-side reinforcing ribs 98 b which are formed onthe lower surfaces of the intermediate and front parts of the connectingportion 135 and which are integral with the lower part of the posteriorsurface of the rear-side vertically extending portion 88.

The leg-sweep apparatus 10 constructed as described above is disposedinside of the bumper cover 50 such that the upper front-side verticallyextending portion 100, the lower front-side vertically extending portionand the intermediate horizontally extending portion 104 which cooperatewith each other to form the staircase-like portion in the front of theU-shaped portion 84 are inserted into the interior of the lowerprotruding portion 48 of the bumper cover 50 of the front bumper 44. Ina state in which the leg-sweep apparatus 10 is disposed as describedabove, the load-input surface 131 of the upper front-side verticallyextending portion 100 is located so as to be opposed to the innersurface of the lower protruding portion 48 having the convex curvedsurface protruding forward, via a slight clearance therebetween with thehorizontal projection 108 interposed between the inner surface of thelower protruding portion 48 of the bumper cover 50 and the load-inputsurface 131. Further, the upper and lower front-side verticallyextending portions 100, 102 have the mutually same height dimension,whereby the intermediate horizontally extending portion 104 of thestaircase-like portion which is inserted into the interior of the lowerprotruding portion 48 of the bumper cover 50 is located at a middle ofthe lower protruding portion 48 in its height direction. Thus, theleg-sweep apparatus 10 is fixedly positioned in a manner similar to thatdescribed in the illustrated embodiments.

As mentioned above, in the leg-sweep apparatus 10 according to theexemplary fifth embodiment, the U-shaped portion 84 and the reinforcingribs 96, 98 are provided on the front portion 14 of the base plate 12,whereby the front portion 14 has sufficient rigidity with respect to theimpact load while, at the same time, the impact load can be effectivelytransmitted in the length direction and the width direction of the frontportion 14 of the base plate 12. Therefore, the front portion 14 of thebase plate 12 can be effectively prevented from being easily deformed ordeflected by the impact load upon collision of the leg portion 62 of thepedestrian collided with the bumper cover 50.

In the state in which the leg-sweep apparatus 10 is disposed inside ofthe bumper cover 50 of the front bumper 44 as described above, theintermediate horizontally extending portion 104 of the staircase-likeportion which is inserted into the interior of the lower protrudingportion 48 of the bumper cover 50 is located at a middle of the lowerprotruding portion 48 in its height direction, so that a point ofinitial contact of the leg-sweep apparatus 10 with the leg portion 62 ofthe pedestrian is the front end of the intermediate horizontallyextending portion 104 of the staircase-like portion provided on thefront portion 14 of the base plate 12. Accordingly, the impact load isinputted, with high reliability, in the horizontal direction to thefront portion 14 of the base plate 12, effectively avoiding easydeflection of the front portion 14.

Therefore, the present leg-sweep apparatus 10 advantageously avoids adelay of the rise of the impact load in the load characteristics due tothe deflection of the front portion 14 of the base plate 12 by theimpact load inputted thereto.

Further, in the state in which the leg-sweep apparatus 10 is disposedinside of the bumper cover 50 of the front bumper 44 as described above,the load-input surface 131 of the upper front-side vertically extendingportion 100 is opposed to the inner surface of the lower protrudingportion 48 of the bumper cover 50 with a slight clearance therebetween.In addition, the horizontal projection 108 formed integrally on theload-input surface 131 is located between the load-input surface 131 andthe inner surface of the lower protruding portion 48 of the bumper cover50. According to the arrangement, even where the inner surface of thelower protruding portion 48 of the bumper cover 50 has the convex curvedsurface configuration that protrudes frontward, it is possible toeffectively eliminate or restrain the delay of the rise of the impactload in the load characteristics due to the existence of the clearancebetween the inner surface of the lower protruding portion 48 and thefront portion 14 of the base plate 12.

In the present leg-sweep apparatus 10, therefore, sufficientcounterforce with respect to the impact load can be exhibited at earliertiming, so that the leg portion 62 of the pedestrian collided with thefront bumper 44 can be quickly and reliably swept, assuring moreenhanced performance of protecting the leg portion of the pedestrian.

As the horizontally extending portions 128, 130 and the rear-sideU-shaped portions 146, 148 are located at mutually different heightlevels, the moment arm can be advantageously shortened, and the rotationforce generated in the plate member upon inputting of the impact load iseffectively weakened, thereby assuring the effect of preventing theleading end part of the plate member from being deformed to be rolledup.

The leg-sweep apparatus 10 according to the illustrated third throughfifth embodiments may be otherwise embodied.

For instance, the number of the rear-side vertically extending portions124, 126, 88 provided at the front portion 14 of the base plate 12 asthe plate member on the back side of the front-side vertically extendingportion 122, 86 is not limited to those in the illustrated third throughfifth embodiments, but may be three or more.

The thickness and the height of the front-side vertically extendingportion 122, 86 may be made different from those of the rear-sidevertically extending portion 124, 126, 88.

Further, the number of the horizontally extending portion eachconnecting adjacent two of the rear-side vertically extending portions124, 126, 88 that are opposed to each other may be suitably increased ordecreased depending upon the number of the rear-side verticallyextending portions.

The number of the rear-side vertically extending portions 124, 126, 88and the number of the horizontally extending portions 128, 130, 94 maybe suitably determined depending upon the degree of rigidity of thefront portion 14 of the base plate 12 with respect to the impact load,the installation space for the pedestrian protection apparatus, etc.

Further, a connection point of the connecting portion to the rear-sidevertically extending portion may be suitably determined among any pointof the posterior surface of the rear-side vertically extending portionwhich is located at a different height level from a connection point ofthe anterior surface of the rear-side vertically extending portion tothe horizontally extending portion, depending upon the installationspace for the pedestrian protection apparatus, etc.

Where the plurality of horizontally extending portions are respectivelylocated between the front-side vertically extending portion and therear-side vertically extending portion which is opposed thereto andbetween adjacent two of the vertically extending portions which areopposed to each other, for connecting the mutually opposing verticallyextending portions to each other, namely, where there are provided aplurality of U-shaped portions, connection points of each horizontallyextending portion with respect to each vertically extending portion arenot limited to the mutually corresponding ends or edges of eachvertically extending portion as in the illustrated embodiments, but maybe mutually corresponding end portions of each vertically extendingportion nearer to the middle than the end or edges, as long as adjacenttwo of the plurality of horizontally extending portions are located atmutually different height levels.

Where only one U-shaped portion is provided, namely, where thefront-side and rear-side vertically extending portions are respectivelyformed integrally with the front end and rear end of one horizontallyextending portion, the front-side and rear-side vertically extendingportions may not be formed integrally with the respective front and rearends or edges of the horizontally extending portion as in theillustrated embodiments, but at least one of the front-side andrear-side vertically extending portions may be provided at an endportion of the horizontally extending portion nearer to the middle thanthe front end or the rear end thereof, for instance. Further, where thefront-side and rear-side vertically extending portions are respectivelyprovided at the front and rear ends of the horizontally extendingportion, at least one of the front-side and rear-side verticallyextending portions may be made integral, at an end portion thereofnearer to the middle than the vertically opposite ends thereof, with thecorresponding one of the front and rear ends of the horizontallyextending portion.

In other words, where one or plurality of U-shaped portion(s) is/areformed on the leading end part of the front portion of the plate member(the base plate), each U-shaped portion may not be constituted bycombining the entirety of each vertically extending portion and theentirety of each horizontally extending portion, but may be constitutedby combining a part of each vertically extending portion and a part ofeach horizontally extending portion.

The installation structure of the pedestrian protection apparatus on thelower part of the front face of the vehicle is not particularly limitedto that in the illustrated embodiments. Namely, the portion of thevehicle to which the rear portion of the plate member is fixed and themanner of fixing may be variously changed. Further, the pedestrianprotection apparatus may be disposed at the lower part of the vehicleseparately from and independently of the front bumper.

The anterior surface of the front-side vertically extending portionfunctioning as the load-input surface 131 may be constituted by a flatplane that is orthogonal to the horizontal plane.

Where the front-side vertically extending portion is bent atsubstantially right angles at a plurality of locations in the middleportion thereof in the height direction so as to have the staircase-likeform extending in the vertical direction, the front-side verticallyextending portion may be bent at right angles at three or more locationsin its height direction. The bending angle may be somewhat larger orsmaller than 90°.

The staircase-like portion formed by bending the front-side verticallyextending portion as described above may be in a descendingconfiguration in the forward direction, or in a configuration ascendingor descending configuration in the backward direction from a bent statein which the front-side vertically extending portion is bent backward,in addition to the illustrated ascending configuration in the forwarddirection.

In the illustrated third through fifth embodiments, the reinforcing ribs150, 152, 154, 96, 98 are formed as reinforcing portions on the frontportion 14 of the base plate 12. The structure of the reinforcingportions is not particularly limited, provided that the reinforcingportions are capable of preventing easy deformation of the front portion14 of the base plate 12 due to the impact load inputted theretoaccompanied by the collision of the leg portion of the pedestrianagainst the front face of the vehicle. Where the reinforcing portionsare constituted by the illustrated reinforcing ribs 150, 152, 154, 96,98, the configuration, the location, the number, etc., of thereinforcing ribs may be suitably changed. Further, the reinforcingportions are not indispensable in the present invention, and may beeliminated.

In the illustrated first through fifth embodiments, the counterforcewith respect to the impact load generated in the leg-sweep apparatus 10by the collision of the leg portion 62 of the pedestrian against thebumper cover 50 is arranged to act on the vicinity of the shank 66 ofthe leg portion 62 of the pedestrian via the lower protruding portion 48of the bumper cover 50. The portion of the leg portion 62 of thepedestrian on which the counterforce with respect to the impact loadacts may be suitably changed depending upon the installation position ofthe leg-sweep apparatus 10.

It is needless to mention that the principle of the invention isapplicable to any pedestrian protection apparatus installed in variousforms on the front face of vehicles other than the automotive vehicles.

It is to be understood that the present invention may be embodied withvarious other changes and modifications which may occur to those skilledin the art, without departing from the spirit and scope of the inventiondefined in the following claims.

EXAMPLES

To further clarify the present invention, there will be explainedexamples of the invention. It is to be understood that the invention isnot limited to the details of the examples.

Initially, there was prepared, by carrying out injection molding usingpolypropylene, a leg-sweep apparatus (10) shown in FIG. 9 of the presentinvention. In the leg-sweep apparatus, a front portion (14) of a flatbase plate (12) is provided with a U-shaped portion (84) consisting of afront-side vertically extending portion (86), a rear-side verticallyextending portion (88) and a horizontally extending portion (94).Further, a plurality of reinforcing ribs (96, 98) are formed integrallyon the front portion (14), and an anterior surface of the front-sidevertically extending portion (86) is made as a load-input surface (131).The thus prepared leg-sweep apparatus is made as the invention example.In the leg-sweep apparatus of the invention example, the maximum lengthof the base plate in the frontward and backward direction is 300 mm andthe width of the base plate is 1200 mm. The height of the front-side andrear-side vertically extending portions is 25 mm, and the length of thehorizontally extending portion is 15 mm. The thickness of the base plateand each extending portion is 3 mm. Each reinforcing rib has a height of25 mm and a thickness of 1.5-3 mm.

For comparison, apart from the leg-sweep apparatus of the inventionexample, there is prepared, by carrying out injection molding usingpolypropylene, a leg-sweep apparatus having a known structure. In theleg-sweep apparatus, a plurality of first ribs are formed integrally ona front portion of a flat base plate such that the first ribs extend inthe length direction of the base plate and such that the first ribs areopposed to and spaced apart from each other in the width of the baseplate by a suitable distance. Further, a second rib extending in thewidth direction is formed integrally on the front portion so as tointersect the plurality of first ribs. In the thus formed leg-sweepapparatus, the forward end face of the base plate is made as aload-input surface. This leg-sweep apparatus is made as a comparativeexample. The maximum length of the base plate as measured in thefrontward and backward direction and the width of the base plate aremade equal to those in the leg-sweep apparatus of the invention example.The height and the thickness of each of the first ribs and the secondrib are made equal to those of the reinforcing ribs in the leg-sweepapparatus of the invention example.

The thus prepared leg-sweep apparatus of the invention example and theleg-sweep apparatus of the comparative example were installed on afixedly positioned base. Thereafter, an impactor having asemi-cylindrical shape and a weight of 21.3 kg was brought intocollision with each of the load-input surfaces of the two leg-sweepapparatus according to the invention example and the comparativeexample., at a rate of 5.3 m/s. Thus, there were conducted pedestriancollision tests on the supposition of a collision of a pedestrian witheach leg-sweep apparatus, whereby there were examined, for eachapparatus, the portion of the apparatus deformed by the impact loadinputted upon collision of the pedestrian and the amount of deformationof the portion, according to CAE analysis. The simulation results by theCAE analysis of the leg-sweep apparatus of the invention example and thecomparative example are shown in FIG. 11 and FIG. 12, respectively. InFIGS. 11 and 12, the difference in the deformation amount in localportions of each apparatus is indicated by shading.

As shown in FIGS. 11 and 12, it is observed that the portion deformed bythe impact load inputted upon collision of the pedestrian is distributedmore widely at the front portion of the base plate in the leg-sweepapparatus of the invention example than in the leg-sweep apparatus ofthe comparative example. This clearly indicates that the leg-sweepapparatus having the structure according to the present inventionpermits the impact load to be distributed in a wide range at the frontportion of the base plate, thereby effectively preventing deflection ofthe front portion of the base plate due to the impact load inputtedthereto.

1. A pedestrian protection apparatus for a vehicle, comprising a platemember which is disposed at a lower part of a front face of the vehicleso as to extend in a frontward and backward direction of the vehicle,which is made of a synthetic resin, which includes a front portion and arear portion, and which is fixed at the rear portion to the vehicle withat least a leading end part of the front portion protruded from thefront face of the vehicle, the apparatus being arranged to sweep a legportion of a pedestrian that has collided with the front face of thevehicle by contact of the leading end part of the front portion of theplate member with the leg portion of the pedestrian, thereby protectingthe leg portion of the pedestrian, wherein the leading end part of thefront portion of the plate member includes at least one horizontallyextending portion each of which extends horizontally in the frontwardand backward direction of the vehicle and a plurality of verticallyextending portions each of which has an anterior surface substantiallyorthogonal to a horizontal plane and each of which extends in a verticaldirection, the at least one horizontally extending portion and theplurality of vertically extending portions being formed integrally withthe leading end part such that each of the at least one horizontallyextending portion and each of the plurality of vertically extendingportions are alternately disposed in the frontward and backwarddirection of the vehicle so as to extend in a staircase-like form,whereby the leading end part has a staircase-like portion constituted bythe at least one horizontally extending portion and the plurality ofvertically extending portions.
 2. The apparatus according to claim 1,wherein a forward end of the staircase-like portion is constituted byone of the plurality of vertically extending portions, and wherein oneof vertically opposite ends of said one of the plurality of verticallyextending portions that is nearer to one of the at least onehorizontally extending portion which is adjacent to said one of theplurality of vertically extending portions is located at a middleportion of the staircase-like portion in a height direction thereof. 3.The apparatus according to claim 1, wherein a forward end of thestaircase-like portion is constituted by one of the at least onehorizontally extending portion.
 4. The apparatus according to claim 1,wherein reinforcing ribs for reinforcing the front portion of the platemember are formed on a part of the front portion that at least includesthe staircase-like portion, such that the reinforcing ribs are integralwith posterior surfaces of the plurality of vertically extendingportions in the staircase-like portion, so as to extend in the frontwardand backward direction of the vehicle.
 5. A pedestrian protectionapparatus for a vehicle, comprising a plate member which is disposed ata lower part of a front face of the vehicle so as to extend in afrontward and backward direction of the vehicle with a suitable width,which is made of a synthetic resin, which includes a front portion and arear portion, and which is fixed at the rear portion to the vehicle withat least a leading end part of the front portion protruded from thefront face of the vehicle, the apparatus being arranged to sweep a legportion of a pedestrian that has collided with the front face of thevehicle by contact of the leading end part of the front portion of theplate member with the leg portion of the pedestrian, thereby protectingthe leg portion of the pedestrian, wherein the plate member includes: ahorizontally extending portion which is located at the leading end partof the front portion of the plate member so as to horizontally extendover an entire width of the plate member; a front-side verticallyextending portion which is formed integrally with a front end of thehorizontally extending portion so as to extend in a vertical direction;a rear-side vertically extending portion which is formed integrally witha rear end of the horizontally extending portion so as to extend in thevertical direction such that the rear-side vertically extending portionis opposed to the front-side vertically extending portion with asuitable distance interposed therebetween; and a connecting portionwhich is constituted by a proximal end part of the front portion of theplate member that extends in the frontward and backward direction on theback side of the rear-side vertically extending portion and whichconnects, integrally to the rear portion of the plate member, aposterior surface of the rear-side vertically extending portion at apoint thereof having a height position different from a height positionof a connecting point of an anterior surface of the rear-side verticallyextending portion at which the rear-side vertically extending portion isconnected to the horizontally extending portion, and wherein the frontportion of the plate member is constituted by including, at the leadingend part thereof, a U-shaped portion having a U-shaped configuration invertical cross section.
 6. The apparatus according to claim 5, whereinthe front-side vertically extending portion is bent at substantiallyright angles at a plurality of locations of a middle portion thereof asseen in a height direction thereof, so as to extend in the verticaldirection in a staircase-like form.
 7. The apparatus according to claim5, wherein reinforcing portions for increasing strength of the frontportion of the plate member is provided on the front portion, so as toprevent easy deformation of the front portion due to an impact loadapplied thereto resulting from collision of the leg portion of thepedestrian with the front face of the vehicle.
 8. The apparatusaccording to claim 7, wherein the reinforcing portions are constitutedby reinforcing ribs formed integrally on the front portion of the platemember such that the reinforcing ribs are integral with a posteriorsurface of the front-side vertically extending portion and posteriorsurfaces of the plurality of rear-side vertically extending portions, soas to extend in the frontward and backward direction.
 9. A pedestrianprotection apparatus for a vehicle, comprising a plate member which isdisposed at a lower part of a front face of the vehicle so as to extendin a frontward and backward direction of the vehicle with a suitablewidth, which is made of a synthetic resin, which includes a frontportion and a rear portion, and which is fixed at the rear portion tothe vehicle with at least a leading end part of the front portionprotruded from the front face of the vehicle, the apparatus beingarranged to sweep a leg portion of a pedestrian that has collided withthe front face of the vehicle by contact of the leading end part of thefront portion of the plate member with the leg portion of thepedestrian, thereby protecting the leg portion of the pedestrian,wherein the plate member includes: a front-side vertically extendingportion which is located at the leading end part of the front portion ofthe plate member so as to vertically extend over an entire width of theplate member; a plurality of rear-side vertically extending portionswhich are located at the back of the front-side vertically extendingportion with a suitable distance interposed therebetween so as to extendin the vertical direction over the entire width of the plate member suchthat the plurality of rear-side vertically extending portions areopposed to the front-side vertically extending portion and spaced apartfrom each other by a suitable distance in the frontward and backwarddirection; a plurality of horizontally extending portions which arelocated between mutually corresponding vertical ends of a forwardmostone of the plurality of rear-side vertically extending portions and thefront-side vertically extending portion and between mutuallycorresponding vertical ends of the plurality of rear-side verticallyextending portions, such that the plurality of horizontally extendingportions horizontally extend over the entire width of the plate memberand such that adjacent two of the plurality of horizontally extendingportions in the frontward and backward direction are located at mutuallydifferent height levels, thereby connecting the front-side verticallyextending portion and the forwardmost one of the plurality of rear-sidevertically extending portions integrally to each other and connectingthe plurality of rear-side vertically extending portions to each other;and a connecting portion which is constituted by a proximal end part ofthe front portion of the plate member that is located on the back sideof a rearmost one of the plurality of rear-side vertically extendingportions so as to extend in the frontward and backward direction andwhich connects, integrally to the rear portion of the plate member, aposterior surface of the rearmost one of the plurality of rear-sidevertically extending portions at a point thereof having a differentheight position from that of a connecting point of an anterior surfaceof the rearmost one of the plurality of vertically extending portions atwhich the rearmost one of the plurality of vertically extending portionsis connected to a corresponding one of the plurality of horizontallyextending portions, and wherein the leading end part of the frontportion of the plate member extends in a zigzag form in a heightdirection with a U-shaped configuration in vertical cross section. 10.The apparatus according to claim 9, wherein the front-side verticallyextending portion is bent at substantially right angles at a pluralityof locations of a middle portion thereof as seen in a height directionthereof, so as to extend in the vertical direction in a staircase-likeform.
 11. The apparatus according to claim 9, wherein reinforcingportions for increasing strength of the front portion of the platemember is provided on the front portion, so as to prevent easydeformation of the front portion due to an impact load applied theretoresulting from collision of the leg portion of the pedestrian with thefront face of the vehicle.
 12. The apparatus according to claim 11,wherein the reinforcing portions are constituted by reinforcing ribsformed integrally on the front portion of the plate member such that thereinforcing ribs are integral with a posterior surface of the front-sidevertically extending portion and posterior surfaces of the plurality ofrear-side vertically extending portions, so as to extend in thefrontward and backward direction.